C++: Difference between revisions
←Replaced content with '{{Infobox programming language I love connor Potter' Tag: blanking |
m Reverted edits by 195.194.74.204 to last revision by 70.52.160.3 (HG) |
||
Line 1: | Line 1: | ||
{{Infobox programming language |
{{Infobox programming language |
||
| name = C++ |
|||
I love connor Potter |
|||
| logo = [[Image:C plus plus book.jpg|150px]] |
|||
| caption = ''[[The C++ Programming Language]]'', written by its architect, is the seminal book on the language. |
|||
| paradigm = [[Multi-paradigm programming language|Multi-paradigm]]: [[procedural programming|procedural]], [[object-oriented programming|object-oriented]], [[generic programming|generic]] |
|||
| year = 1983 |
|||
| designer = [[Bjarne Stroustrup]] |
|||
| developer = Bjarne Stroustrup<br/>[[Bell Labs]]<br/>{{nobr|ISO/IEC JTC1/SC22/WG21}} |
|||
| latest_release_version = |
|||
| latest_release_date = [[1998]] |
|||
| latest_test_version = [[C++0x]] |
|||
| latest_test_date = |
|||
| turing-complete = Yes |
|||
| typing = [[Type system#Static typing|Static]], [[Type system#Safely and unsafely typed systems|unsafe]], [[Nominative type system|nominative]] |
|||
| implementations = [[Borland C++ Builder]], [[GNU Compiler Collection|GCC]], [[Intel C++ Compiler]], [[Microsoft Visual C++]], [[Sun Studio (software)|Sun Studio]], [[Turbo C++]], [[Comeau C/C++]] |
|||
| dialects = [[ISO/IEC 14882|ISO/IEC C++]] 1998, [[ISO/IEC 14882|ISO/IEC C++]] 2003 |
|||
| influenced_by = [[C (programming language)|C]], [[Simula]], [[Ada (programming language)|Ada 83]], [[ALGOL 68]], [[CLU programming language|CLU]], [[ML (programming language)|ML]]<ref>{{cite book|last=Stroustrup|first=Bjarne|title=The C++ Programming Language|date=1997|edition=Third|chapter=1|isbn=0201889544|oclc=59193992|accessdate=25 February 2010|language=English}}</ref> |
|||
| influenced = [[Perl]]<!--1987-->, [[Lua (programming language)|Lua]]<!--1993-->, [[Ada (programming language)|Ada 95]]<!--1995-->, [[Java (programming language)|Java]]<!--1995-->, [[PHP]]<!--1995-->, [[D programming language|D]]<!--1999-->, [[C99]]<!--1999-->, [[C Sharp (programming language)|C#]]<!--2001-->, [[Aikido (programming language)|Aikido]]<!--2003-->, [[Falcon (programming language)|Falcon]]<!--2003-->, [[Dao (programming language)|Dao]]<!--2006--> |
|||
| operating_system = [[Cross-platform|Cross-platform (multi-platform)]] |
|||
| license = |
|||
| website = |
|||
| file_ext = .hh .hpp .hxx .h++ .cc .cpp .cxx .c++ |
|||
}} |
|||
'''C++''' (pronounced "see plus plus") is a [[Type system#Static typing|statically typed]], [[free-form language|free-form]], [[multi-paradigm programming language|multi-paradigm]], [[compiled language|compiled]], general-purpose [[programming language]]. It is regarded as a ''middle-level'' language, as it comprises a combination of both [[high-level programming language|high-level]] and [[low-level programming language|low-level]] language features.<ref>C++ The Complete Reference Third Edition, Herbert Schildt, Publisher: Osborne McGraw-Hill.</ref> It was developed by [[Bjarne Stroustrup]] starting in 1979 at [[Bell Labs]] as an enhancement to the [[C (programming language)|C programming language]] and originally named "''C with Classes''". It was renamed ''C++'' in 1983.<ref>[http://www2.research.att.com/~bs/bs_faq.html#invention ATT.com]</ref> |
|||
As one of the most popular programming languages ever created,<ref>{{cite web | url = http://www.langpop.com/ | title = Programming Language Popularity | year = 2009 | accessdate = 2009-01-16}}</ref><ref>{{cite web | url = http://www.tiobe.com/index.php/content/paperinfo/tpci/index.html | title = TIOBE Programming Community Index | year = 2009 | accessdate = 2009-05-06}}</ref> C++ is widely used in the software industry. Some of its application domains include systems software, application software, device drivers, embedded software, high-performance server and client applications, and entertainment software such as [[video games]]. Several groups provide both free and proprietary C++ [[compiler]] software, including the [[GNU Compiler Collection|GNU Project]], [[Microsoft Visual C++|Microsoft]], [[Intel C++ Compiler|Intel]] and [[Borland C++ Builder|Borland]]. C++ has greatly influenced many other popular programming languages, most notably [[Java (programming language)|Java]]. |
|||
C++ is also used for [[hardware design]], where design is initially described in C++, then analyzed, architecturally constrained, and scheduled to create a [[register transfer level]] [[hardware description language]] via [[high-level synthesis]]. |
|||
The language began as enhancements to [[C (programming language)|''C'']], first adding [[class (computer science)|classes]], then [[virtual functions]], [[operator overloading]], [[multiple inheritance]], [[template (programming)|templates]], and [[exception handling]] among other features. After years of development, the C++ programming language standard was ratified in 1998 as ''[[ISO/IEC 14882]]:1998''. That standard is still current, but is amended by the 2003 technical [[Errata|corrigendum]], ''ISO/IEC 14882:2003''. The next standard version (known informally as [[C++0x]]) is in development. |
|||
{{TOC limit|limit=3}} |
|||
== History == |
|||
[[Image:BjarneStroustrup.jpg|thumb|[[Bjarne Stroustrup]], creator of C++]] |
|||
Stroustrup began work on "C with Classes" in 1979. The idea of creating a new language originated from Stroustrup's experience in programming for his Ph.D. thesis. Stroustrup found that [[Simula]] had features that were very helpful for large software development, but the language was too slow for practical use, while [[BCPL]] was fast but too low-level to be suitable for large software development. When Stroustrup started working in [[AT&T Bell Labs]], he had the problem of analyzing the [[Unix|UNIX]] [[Kernel (computer science)|kernel]] with respect to [[distributed computing]]. Remembering his Ph.D. experience, Stroustrup set out to enhance the [[C (programming language)|C]] language with [[Simula]]-like features. C was chosen because it was general-purpose, fast, portable and widely used. Besides C and Simula, some other languages that inspired him were [[ALGOL 68]], [[Ada programming language|Ada]], [[CLU programming language|CLU]] and [[ML programming language|ML]]. At first, the class, derived class, strong type checking, [[inlining]], and default argument features were added to C via Stroustrup's C++ to C compiler, [[Cfront]]. The first commercial implementation of C++ was released in October 1985.<ref name="invention">{{cite web|url=http://public.research.att.com/~bs/bs_faq.html#invention|title=Bjarne Stroustrup's FAQ — When was C++ invented?|accessdate=30 May 2006}}</ref> |
|||
In 1983, the name of the language was changed from ''C with Classes'' to C++ (++ being the [[Increment|increment operator]] in C and C++). New features were added including [[virtual function]]s, function name and operator overloading, references, constants, user-controlled free-store memory control, improved type checking, and BCPL style single-line comments with two forward slashes (//). In 1985, the first edition of ''[[The C++ Programming Language]]'' was released, providing an important reference to the language, since there was not yet an official standard. Release 2.0 of C++ came in 1989. New features included multiple inheritance, abstract classes, static member functions, [[const correctness|const member functions]], and protected members. In 1990, ''The Annotated C++ Reference Manual'' was published. This work became the basis for the future standard. Late addition of features included [[template (programming)|template]]s, [[exceptions]], [[Namespace (computer science)|namespaces]], new [[cast (computer science)|cast]]s, and a [[Boolean datatype|Boolean type]]. |
|||
As the C++ language evolved, a standard library also evolved with it. The first addition to the C++ standard library was the [[iostream|stream I/O library]] which provided facilities to replace the traditional C functions such as [[printf]] and [[scanf]]. Later, among the most significant additions to the standard library, was the [[Standard Template Library]]. |
|||
C++ continues to be used and is one of the preferred programming languages to develop professional applications. The popularity of the language continues to grow.<ref name="present day">{{cite web|url=http://www.odesk.com/trends/c%2B%2B|title=Trends on C++ Programmers, Developers & Engineers|accessdate=1 December 2008}}</ref> |
|||
===Language standard === |
|||
In 1998, the C++ standards committee (the [[International Organization for Standardization|ISO]]/[[International Electrotechnical Commission|IEC]] [[SC22|JTC1/SC22/WG21]] [[working group]]) standardized C++ and published the international standard ''ISO/IEC 14882:1998'' (informally known as ''C++98''<ref>{{cite web |
|||
| last = Stroustrup |
|||
| first = Bjarne |
|||
| title = C++ Glossary |
|||
| url=http://www.research.att.com/~bs/glossary.html |
|||
| accessdate = 8 June 2007 }}</ref>). For some years after the official release of the standard, the committee processed defect reports, and published a corrected version of the C++ standard, ''ISO/IEC 14882:2003'', in 2003. In 2005, a technical report, called the "[[Technical Report 1|Library Technical Report 1]]" (often known as TR1 for short), was released. While not an official part of the standard, it specified a number of extensions to the standard library, which were expected to be included in the next version of C++. Support for TR1 is growing in almost all currently maintained C++ compilers. |
|||
The standard for the next version of the language (known informally as [[C++0x]]) is in development. |
|||
=== Etymology === |
|||
According to Stroustrup: "the name signifies the evolutionary nature of the changes from C".<ref name="name">{{cite web|url=http://public.research.att.com/~bs/bs_faq.html#name|title=Bjarne Stroustrup's FAQ — Where did the name "C++" come from?|accessdate=16 January 2008}}</ref> During C++'s development period, the language had been referred to as "new C", then "C with Classes". The final name is credited to [[Rick Mascitti]] (mid-1983) and was first used in December 1983. When Mascitti was questioned informally in 1992 about the naming, he indicated that it was given in a [[tongue-in-cheek]] spirit. It stems from C's "++" [[operator]] (which increments the [[Value (computer science)|value]] of a [[Variable (programming)|variable]]) and a common [[naming convention]] of using "+" to indicate an enhanced computer program. There is no language called "C plus". [[ABCL/c+]] was the name of an earlier, unrelated programming language. |
|||
== Philosophy == |
|||
In ''[[The Design and Evolution of C++]]'' (1994), Bjarne Stroustrup describes some rules that he used for the design of C++: |
|||
* C++ is designed to be a [[statically typed]], general-purpose language that is as efficient and portable as C |
|||
* C++ is designed to directly and comprehensively support multiple programming styles ([[procedural programming]], [[data abstraction]], [[object-oriented programming]], and [[generic programming]]) |
|||
* C++ is designed to give the [[programmer]] choice, even if this makes it possible for the programmer to choose incorrectly |
|||
* C++ is designed to be as compatible with C as possible, therefore providing a smooth transition from C |
|||
* C++ avoids features that are platform specific or not general purpose |
|||
* C++ does not incur overhead for features that are not used (the "zero-overhead principle") |
|||
* C++ is designed to function without a sophisticated programming environment |
|||
Stroustrup also mentions that C++ was always intended to make programming more ''fun'' and that many of the double meanings in the language are intentional. |
|||
''Inside the C++ Object Model'' (Lippman, 1996) describes how compilers may convert C++ program statements into an in-memory layout. Compiler authors are, however, free to implement the standard in their own manner. |
|||
==Standard library== |
|||
The 1998 [[American National Standards Institute|ANSI]]/[[International Organization for Standardization|ISO]] C++ [[standardization|standard]] consists of two parts: the [[core language]] and the [[C++ Standard Library]]; the latter includes most of the [[Standard Template Library]] (STL) and a slightly modified version of the C standard library. Many C++ libraries exist which are not part of the standard, and, using linkage specification, libraries can even be written in languages such as [[C (programming language)|C]], [[Fortran]], [[Pascal (programming language)|Pascal]], or [[BASIC]]. Which of these are supported is compiler dependent. |
|||
The C++ standard library incorporates the C standard library with some small modifications to make it optimized with the C++ language. Another large part of the C++ library is based on the STL. This provides such useful tools as [[container (data structure)|container]]s (for example [[Array data structure|vector]]s and [[linked list|lists]]), [[iterator]]s to provide these containers with array-like access and [[algorithm]]s to perform operations such as searching and sorting. Furthermore (multi)maps ([[associative array]]s) and (multi)sets are provided, all of which export compatible interfaces. Therefore it is possible, using templates, to write generic algorithms that work with any container or on any sequence defined by iterators. As in C, the [[feature (software design)|feature]]s of the [[Library (computing)|library]] are accessed by using the <code>#include</code> [[directive (programming)|directive]] to include a [[standard header]]. C++ provides [[C++ standard library#Standard headers|69 standard headers]], of which 19 are deprecated. |
|||
The STL was originally a third-party library from [[Hewlett-Packard|HP]] and later [[Silicon Graphics|SGI]], before its incorporation into the C++ standard. The standard does not refer to it as "STL", as it is merely a part of the standard library, but many people still use that term to distinguish it from the rest of the library (input/output streams, internationalization, diagnostics, the C library subset, etc.). |
|||
Most C++ compilers provide an implementation of the C++ standard library, including the STL. Compiler-independent implementations of the STL, such as STLPort,<ref name="stlport">[http://www.stlport.org/ STLPort home page], quote from "The C++ Standard Library" by Nicolai M. Josuttis, p138., ISBN 0-201 37926-0, [[Addison-Wesley]], 1999: "An exemplary version of STL is the STLport, which is available for free for any platform"</ref> also exist. Other projects also produce various custom implementations of the C++ standard library and the STL with various design goals. |
|||
==Language features== |
|||
C++ inherits most of C's syntax and the [[C preprocessor]]. The following is Bjarne Stroustrup's version of the [[Hello world program]] which uses the [[C++ standard library]] stream facility to write a message to [[Standard output#Standard output .28stdout.29|standard output]]:<ref>{{ cite book | first = Bjarne | last = Stroustrup | authorlink = Bjarne Stroustrup | year = 2000 | page = 46 | title = The C++ Programming Language | edition = Special Edition | publisher = Addison-Wesley | isbn = 0-201-70073-5 }}</ref><ref>[http://www.research.att.com/~bs/3rd_issues.html Open issues for The C++ Programming Language (3rd Edition)] - This code is copied directly from Bjarne Stroustrup's errata page (p. 633). He addresses the use of <code>'\n'</code> rather than <code>std::endl</code>. |
|||
Also see [http://www.research.att.com/~bs/bs_faq2.html#void-main www.research.att.com] for an explanation of the implicit <code>return 0;</code> in the <code>main</code> function. This implicit return is ''not'' available in other functions.</ref> |
|||
<!-- |
|||
*************************************************************** |
|||
* |
|||
* PLEASE NOTE: |
|||
* |
|||
* BEFORE MAKING CHANGES to the "Hello World" example |
|||
* please establish consensus by discussing your proposed changes |
|||
* on the Talk page. This is not the place to "Be Bold"; this |
|||
* has been discussed before. |
|||
* |
|||
* If you change the sample program without discussion, it will be |
|||
* reverted within a few minutes. |
|||
* |
|||
* Yes, you could say "using namespace std;" or "using std::cout;". |
|||
* Yes, you could use "std::endl" rather than "\n". |
|||
* Yes, you could add "return 0;" at the end. |
|||
* Yes, you could add "int argc, char ** argv" to main. |
|||
* Yes, your ancient compiler might require "#include <iostream.h>". |
|||
* Yes, you could use "printf" from the Standard C Library. |
|||
* |
|||
* But don't. |
|||
* |
|||
* The latest consensus is NOT to make any of those changes. |
|||
* This is the example "Hello, world!" by Bjarne Stroustrup, |
|||
* the author of the C++ language, and is used in |
|||
* his book, "The C++ Programming Language (3rd edition)". |
|||
* |
|||
*************************************************************** |
|||
--><source lang="cpp"> |
|||
#include <iostream> |
|||
int main() |
|||
{ |
|||
std::cout << "Hello, world!\n"; |
|||
} |
|||
</source><!-- |
|||
***PLEASE NOTE:**** |
|||
* BEFORE MAKING CHANGES to the "Hello World" example |
|||
* please establish consensus by discussing your proposed changes |
|||
* on the Talk page. This is not the place to "Be Bold"; this |
|||
* has been discussed before. |
|||
* |
|||
* If you change the sample program without discussion, it will be |
|||
* reverted within a few minutes. |
|||
* |
|||
* Yes, you could say "using namespace std;" or "using std::cout;". |
|||
* Yes, you could use "std::endl" rather than "\n". |
|||
* Yes, you could add "return 0;" at the end. |
|||
* Yes, you could add "int argc, char ** argv" to main. |
|||
* Yes, your ancient compiler might require "#include <iostream.h>". |
|||
* Yes, you could use "printf" from the Standard C Library. |
|||
* |
|||
* But don't. |
|||
* |
|||
* The latest consensus is NOT to make any of those changes. |
|||
* This is the example "Hello, world!" by Bjarne Stroustrup, |
|||
* the author of the C++ language, and is used in |
|||
* his book, "The C++ Programming Language (3rd edition)". |
|||
* |
|||
***************************************************************--> |
|||
The C++ standard requires the main function to be defined with <code>int</code> as its return type, but it need not return a value with an explicit return statement, as an implicit <code>return 0</code> is executed when the end of <code>main</code> is reached.<ref name="C++03 3.6.1/5">[[ISO]]/[[International Electrotechnical Commission|IEC]] (2003). ''[[ISO/IEC 14882|ISO/IEC 14882:2003(E): Programming Languages - C++]] §3.6.1 Main function [basic.start.main]'' para. 5</ref> Such an implicit <return> rule does not apply to any other value-returning functions: If control reaches their closing <code>}</code> [[undefined behavior]] results.<ref name="C++03 6.6.3/2">[[ISO]]/[[International Electrotechnical Commission|IEC]] (2003). ''[[ISO/IEC 14882|ISO/IEC 14882:2003(E): Programming Languages - C++]] §6.6.3 The return statement [stmt.return]'' para. 2</ref> |
|||
===Operators and operator overloading=== |
|||
C++ provides more than [[Operators in C and C++|30 operators]], covering basic arithmetic, bit manipulation, indirection, comparisons, logical operations and others. Almost all operators can be [[Operator overloading|overloaded]] for user-defined types, with a few notable exceptions such as member access (. and .*). The rich set of overloadable operators is central to using C++ as a [[domain specific language]]. The overloadable operators are also an essential part of many advanced C++ programming techniques, such as [[smart pointer]]s. Overloading an operator does not change the precedence of calculations involving the operator, nor does it change the number of operands that the operator uses (any operand may however be ignored by the operator, though it will be evaluated prior to execution). |
|||
===Templates=== |
|||
{{See also|generic programming|template metaprogramming}} |
|||
C++ templates enable [[generic programming]]. C++ supports both function and class templates. Templates may be parameterized by types, compile-time constants, and other templates. C++ templates are implemented by ''instantiation'' at compile-time. To instantiate a template, compilers substitute specific arguments for a template's parameters to generate a concrete function or class instance. Some substitutions are not possible; these are eliminated by an overload resolution policy described by the phrase "[[Substitution failure is not an error]]" (SFINAE). Templates are a powerful tool that can be used for [[generic programming]], [[template metaprogramming]], and code optimization, but this power implies a cost. Template use may increase code size, since each template instantiation produces a copy of the template code: one for each set of template arguments. This is in contrast to run-time generics seen in other languages (e.g. [[Generics in Java|Java]]) where at compile-time the type is erased and a single template body is preserved. |
|||
Templates are different from macros: while both of these compile-time language features enable conditional compilation, templates are not restricted to lexical substitution. Templates are aware of the semantics and type system of their companion language, as well as all compile-time type definitions, and can perform high-level operations including programmatic flow control based on evaluation of strictly type-checked parameters. Macros are capable of conditional control over compilation based on predetermined criteria, but cannot instantiate new types, recurse, or perform type evaluation and in effect are limited to pre-compilation text-substitution and text-inclusion/exclusion. In other words, macros can control compilation flow based on pre-defined symbols but cannot, unlike templates, independently instantiate new symbols. Templates are a tool for static [[Polymorphism in object-oriented programming|polymorphism]] (see below) and [[generic programming]]. |
|||
In addition, templates are a compile time mechanism in C++ which is [[Turing-complete]], meaning that any computation expressible by a computer program can be computed, in some form, by a [[template metaprogramming|template metaprogram]] prior to runtime. |
|||
In summary, a template is a compile-time parameterized function or class written without knowledge of the specific arguments used to instantiate it. After instantiation the resulting code is equivalent to code written specifically for the passed arguments. In this manner, templates provide a way to decouple generic, broadly-applicable aspects of functions and classes (encoded in templates) from specific aspects (encoded in template parameters) without sacrificing performance due to abstraction. |
|||
===Objects=== |
|||
{{Main|C++ classes}} |
|||
C++ introduces [[object-oriented]] (OO) features to C. It offers [[class (computer science)|class]]es, which provide the four features commonly present in OO (and some non-OO) languages: [[Abstraction (computer science)|abstraction]], [[Information hiding|encapsulation]], [[Inheritance (object-oriented programming)|inheritance]], and [[Polymorphism (computer science)|polymorphism]]. Objects are instances of classes created at runtime. The class can be thought of as a template from which many different individual objects may be generated as a program runs. |
|||
====Encapsulation==== |
|||
[[information hiding|Encapsulation]] is the hiding of information in order to ensure that data structures and operators are used as intended and to make the usage model more obvious to the developer. C++ provides the ability to define classes and functions as its primary encapsulation mechanisms. Within a class, members can be declared as either public, protected, or private in order to explicitly enforce encapsulation. A public member of the class is accessible to any function. A private member is accessible only to functions that are members of that class and to functions and classes explicitly granted access permission by the class ("friends"). A protected member is accessible to members of classes that inherit from the class in addition to the class itself and any friends. |
|||
The OO principle is that all of the functions (and only the functions) that access the internal representation of a type should be encapsulated within the type definition. C++ supports this (via member functions and friend functions), but does not enforce it: the programmer can declare parts or all of the representation of a type to be public, and is allowed to make public entities that are not part of the representation of the type. Because of this, C++ supports not just OO programming, but other weaker decomposition paradigms, like [[Modularity (programming)|modular programming]]. |
|||
It is generally considered good practice to make all [[data]] private or protected, and to make public only those functions that are part of a minimal interface for users of the class. This hides all the details of data implementation, allowing the designer to later fundamentally change the implementation without changing the interface in any way.<ref name="cppcs">{{ cite book |
|||
| first1 = Herb |
|||
| last1 = Sutter |
|||
| first2 = Andrei |
|||
| last2 = Alexandrescu |
|||
| authorlink1 = Herb Sutter |
|||
| authorlink2 = Andrei Alexandrescu |
|||
| year = 2004 |
|||
| title = C++ Coding Standards: 101 Rules, Guidelines, and Best Practices |
|||
| publisher = Addison-Wesley |
|||
}} |
|||
</ref><ref name="industrialcpp">{{cite book |
|||
|last1=Henricson |
|||
|first1=Mats |
|||
|last2=Nyquist |
|||
|first2=Erik |
|||
|title=Industrial Strength C++ |
|||
|publisher=Prentice Hall |
|||
|date=1997 |
|||
|isbn=ISBN 0-13-120965-5}} |
|||
</ref> |
|||
====Inheritance==== |
|||
[[Inheritance (computer science)|Inheritance]] allows one data type to acquire properties of other data types. Inheritance from a base class may be declared as public, protected, or private. This access specifier determines whether unrelated and derived classes can access the inherited public and protected members of the base class. Only public inheritance corresponds to what is usually meant by "inheritance". The other two forms are much less frequently used. If the access specifier is omitted, a "class" inherits privately, while a "struct" inherits publicly. Base classes may be declared as virtual; this is called [[virtual inheritance]]. Virtual inheritance ensures that only one instance of a base class exists in the inheritance graph, avoiding some of the ambiguity problems of [[multiple inheritance]]. |
|||
'''[[Multiple inheritance]]''' is a C++ feature sometimes considered controversial. Multiple inheritance allows a class to be derived from more than one base class; this can result in a complicated graph of inheritance relationships. For example, a "Flying Cat" class can inherit from both "Cat" and "Flying Mammal". Some other languages, such as [[Java (programming language)|Java]] or [[C Sharp (programming language)|C#]], accomplish something similar (although more limited) by allowing inheritance of multiple [[Interface (computer science)|interfaces]] while restricting the number of base classes to one (interfaces, unlike classes, provide only declarations of member functions, no implementation or member data). Interfaces and abstract classes in Java and C# can be defined in C++ as a class containing only pure virtual functions, often known as an abstract base class or "ABC." Programmers preferring the Java/C# model of inheritance can choose to inherit only one non-abstract class, although in this case the declared member functions of the abstract base classes must be explicitly defined and cannot be inherited. |
|||
===Polymorphism=== |
|||
{{See also|Polymorphism in object-oriented programming}} |
|||
[[Type polymorphism|Polymorphism]] enables one common interface for many implementations, and for objects to act differently under different circumstances. |
|||
C++ supports several kinds of ''static'' ([[compile-time]]) and ''dynamic'' ([[run-time]]) [[polymorphism (computer science)|polymorphism]]s. Compile-time polymorphism does not allow for certain run-time decisions, while run-time polymorphism typically incurs a performance penalty. |
|||
====Static polymorphism==== |
|||
[[Function overloading]] allows programs to declare multiple functions having the same name (but with different arguments). The functions are distinguished by the number and/or types of their [[Parameter (computer science)|formal parameter]]s. Thus, the same function name can refer to different functions depending on the context in which it is used. The type returned by the function is not used to distinguish overloaded functions. |
|||
When declaring a function, a programmer can specify [[default arguments]] for one or more parameters. Doing so allows the parameters with defaults to optionally be omitted when the function is called, in which case the default arguments will be used. When a function is called with fewer arguments than there are declared parameters, explicit arguments are matched to parameters in left-to-right order, with any unmatched parameters at the end of the parameter list being assigned their default arguments. In many cases, specifying default arguments in a single function declaration is preferable to providing overloaded function definitions with different numbers of parameters. |
|||
[[Generic programming#Templates|Templates]] in C++ provide a sophisticated mechanism for writing generic, polymorphic code. In particular, through the [[Curiously Recurring Template Pattern]] it's possible to implement a form of static polymorphism that closely mimics the syntax for overriding virtual functions. Since C++ templates are type-aware and [[Turing-complete]] they can also be used to let the compiler resolve recursive conditionals and generate substantial programs through [[template metaprogramming]]. |
|||
====Dynamic polymorphism==== |
|||
=====Inheritance===== |
|||
Variable pointers (and references) to a base class type in C++ can refer to objects of any derived classes of that type in addition to objects exactly matching the variable type. This allows arrays and other kinds of containers to hold pointers to objects of differing types. Because assignment of values to variables usually occurs at run-time, this is necessarily a run-time phenomenon. |
|||
C++ also provides a <code>dynamic_cast</code> operator, which allows the program to safely attempt conversion of an object into an object of a more specific object type (as opposed to conversion to a more general type, which is always allowed). This feature relies on [[run-time type information]] (RTTI). Objects known to be of a certain specific type can also be cast to that type with <code>static_cast</code>, a purely compile-time construct which is faster and does not require RTTI. |
|||
=====Virtual member functions===== |
|||
Ordinarily when a function in a derived class [[Method overriding (programming)|overrides]] a function in a base class, the function to call is determined by the type of the object. A given function is overridden when there exists no difference, in the number or type of parameters, between two or more definitions of that function. Hence, at compile time it may not be possible to determine the type of the object and therefore the correct function to call, given only a base class pointer; the decision is therefore put off until runtime. This is called [[dynamic dispatch]]. [[virtual functions|Virtual member functions]] or ''methods''<ref>{{cite book | quote = A virtual member function is sometimes called a ''method''.| first = Bjarne | last = Stroustrup | authorlink = Bjarne Stroustrup | year = 2000 | page = 310 | title = The C++ Programming Language | edition = Special Edition | publisher = Addison-Wesley | isbn = 0-201-70073-5 }}</ref> allow the most specific implementation of the function to be called, according to the actual run-time type of the object. In C++, this is commonly done using [[virtual function table]]s. If the object type is known, this may be bypassed by prepending a [[fully qualified name|fully qualified class name]] before the function call, but in general calls to virtual functions are resolved at run time. |
|||
In addition to standard member functions, operator overloads and destructors can be virtual. A general rule of thumb is that if any functions in the class are virtual, the destructor should be as well. As the type of an object at its creation is known at compile time, constructors, and by extension copy constructors, cannot be virtual. Nonetheless a situation may arise where a copy of an object needs to be created when a pointer to a derived object is passed as a pointer to a base object. In such a case a common solution is to create a <code>clone()</code> (or similar) function and declare that as virtual. The <code>clone()</code> method creates and returns a copy of the derived class when called. |
|||
A member function can also be made "pure virtual" by appending it with <code>= 0</code> after the closing parenthesis and before the semicolon. Objects cannot be created of a class with a pure virtual function and are called abstract data types. Such abstract data types can only be derived from. Any derived class inherits the virtual function as pure and must provide a non-pure definition of it (and all other pure virtual functions) before objects of the derived class can be created. A program that attempts to create an object of a class with a pure virtual member function or inherited pure virtual member function is ill-formed. |
|||
==Parsing and processing C++ source code== |
|||
It is relatively difficult to write a good C++ [[parser]] with classic parsing algorithms such as [[LALR parser|LALR(1)]].<ref>{{cite web|author=Andrew Birkett |url=http://www.nobugs.org/developer/parsingcpp/ |title=Parsing C++ at nobugs.org |publisher=Nobugs.org |date= |accessdate=3 July 2009}}</ref> This is partly because the C++ grammar is not LALR. Because of this, there are very few tools for analyzing or performing non-trivial transformations (e.g., [[refactoring]]) of existing code. One way to handle this difficulty is to choose a different syntax, such as [[Significantly Prettier and Easier C++ Syntax]], which is LALR(1) parsable. More powerful parsers, such as [[GLR parser]]s, can be substantially simpler (though slower). |
|||
Parsing (in the literal sense of producing a syntax tree) is not the most difficult problem in building a C++ processing tool. Such tools must also have the same understanding of the meaning of the identifiers in the program as a compiler might have. Practical systems for processing C++ must then not only parse the source text, but be able to resolve for each identifier precisely which definition applies (e.g. they must correctly handle C++'s complex scoping rules) and what its type is, as well as the types of larger expressions. |
|||
Finally, a practical C++ processing tool must be able to handle the variety of C++ dialects used in practice (such as that supported by the [[GNU Compiler Collection]] and that of Microsoft's [[Visual C++]]) and implement appropriate analyzers, source code transformers, and regenerate source text. Combining advanced parsing algorithms such as GLR with symbol table construction and [[program transformation]] machinery can enable the construction of arbitrary C++ tools. {{Citation needed|date=October 2009}} |
|||
== Compatibility == |
|||
Producing a reasonably standards-compliant C++ compiler has proven to be a difficult task for compiler vendors in general. For many years, different C++ compilers implemented the C++ language to different levels of compliance to the standard, and their implementations varied widely in some areas such as [[partial template specialization]]. Recent releases of most popular C++ compilers support almost all of the C++ 1998 standard.<ref>{{cite web|url=http://www.ddj.com/dept/cpp/184401381|title=C++ Conformance Roundup|work=[[Dr. Dobb's Journal]]|author=Herb Sutter|date=15 April 2003|accessdate=30 May 2006}}</ref> |
|||
One particular point of contention is the <tt>export</tt> keyword, intended to allow template definitions to be separated from their declarations. The first compiler to implement <tt>export</tt> was [[Comeau C/C++]], in early 2003 (5 years after the release of the standard); in 2004, the beta compiler of [[Borland C++ Builder X]] was also released with <tt>export</tt>. Both of these compilers are based on the [[Edison Design Group|EDG]] C++ front end. Other compilers such as [[GNU Compiler Collection|GCC]] do not support it at all. Many C++ books{{which?|date=November 2009|if there's "many", there's more than one we can mention. A secondary ref that lists examples would be ideal.}} (such as ''Beginning ANSI C++'' by Ivor Horton) provide example code with the keyword that will not compile in most compilers, without reference to this problem. [[Herb Sutter]], former convener of the C++ standards committee, recommended that <tt>export</tt> be removed from future versions of the C++ standard,<ref>{{PDFlink|[http://anubis.dkuug.dk/jtc1/sc22/wg21/docs/papers/2003/n1426.pdf Why We Can’t Afford Export]|266 KB}}</ref> but finally the decision was made to retain it.<ref>{{cite web|url=http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2003/n1459.html|title=Minutes of J16 Meeting No. 36/WG21 Meeting No. 31, April 7-11, 2003|date=25 April 2003|accessdate=4 September 2006}}</ref> |
|||
In order to give compiler vendors greater freedom, the C++ standards committee decided not to dictate the implementation of [[name mangling]], [[exception handling]], and other implementation-specific features. The downside of this decision is that [[object code]] produced by different [[compiler]]s is expected to be incompatible. There are, however, third party standards for particular machines or [[operating system]]s which attempt to standardize compilers on those platforms (for example C++ ABI<ref>{{cite web|url=http://www.codesourcery.com/cxx-abi/|title=C++ ABI|accessdate=30 May 2006}}</ref>); some compilers adopt a secondary standard for these items. |
|||
=== With C === |
|||
{{details|Compatibility of C and C++}} |
|||
C++ is often considered to be a superset of [[C (programming language)|C]], but this is not strictly true.<ref name="superset">{{cite web|url=http://public.research.att.com/~bs/bs_faq.html#C-is-subset|title=Bjarne Stroustrup's FAQ - Is C a subset of C++?|accessdate=18 January 2008}}</ref> Most C code can easily be made to compile correctly in C++, but there are a few differences that cause some valid C code to be invalid in C++, or to behave differently in C++. |
|||
One commonly encountered difference is that C allows implicit conversion from <code>void*</code> to other pointer types, but C++ does not. Another common portability issue is that C++ defines many new keywords, such as <code>new</code> and <code>class</code>, that may be used as identifiers (e.g. variable names) in a C program. |
|||
Some incompatibilities have been removed by the latest [[C99|(C99) C standard]], which now supports C++ features such as <code>//</code> comments and mixed declarations and code. On the other hand, C99 introduced a number of new features that C++ does not support, such as variable-length arrays, native complex-number types, designated initializers and compound literals.<ref>{{cite web|url=http://home.datacomm.ch/t_wolf/tw/c/c9x_changes.html|title=C9X -- The New C Standard|accessdate=27 December 2008}}</ref> However, at least some of the new C99 features will likely be included in the next version of the C++ standard, [[C++0x]]. |
|||
In order to intermix C and C++ code, any function declaration or definition that is to be called from/used both in C and C++ must be declared with C linkage by placing it within an <code>extern "C" {/*...*/}</code> block. Such a function may not rely on features depending on name mangling (i.e., function overloading). |
|||
== Criticism == |
|||
{{See also|Comparison of Java and C++}} |
|||
Critics of the language raise several points. First, since C++ includes C as a subset, it inherits many of the criticisms leveled at C. For its large feature set, it is criticized as being "bloated", over-complicated, and difficult to fully master.<ref>{{cite web | url=http://www.simple-talk.com/opinion/geek-of-the-week/niklaus-wirth-geek-of-the-week/ | title=Niklaus Wirth: Geek of the Week | first=Richard | last=Morris | date=July 2, 2009 | accessdate=8 August 2009 | quote=C++ is a language that was designed to cater to everybody’s perceived needs. As a result, the language and even more so its implementations have become complex and bulky, difficult to understand, and likely to contain errors for ever.}}</ref> Bjarne Stroustrup points out that resultant executables do not support these claims of bloat: "''I have even seen the C++ version of the 'hello world' program smaller than the C version.''"<ref>[http://www.research.att.com/~bs/bs_faq.html#Hello-world Why is the code generated for the "Hello world" program ten times larger for C++ than for C?]</ref> An [[Embedded C++]] standard was proposed to deal with part of this, but criticized for leaving out useful parts of the language that incur no runtime penalty.<ref>[http://www.research.att.com/~bs/bs_faq.html#EC++ What do you think of EC++?]</ref> |
|||
C++ is more complex than some other programming languages. The ISO standard of the C++ language is about 310 pages (excluding the definitions of what is in the library). For comparison, the C programming language standard, written eight years earlier, is about 160 pages, and [[C Sharp (programming language)|C#]]'s [[ECMA]] language definition document is about 440 pages. Bjarne Stroustrup points out that "''The programming world is far more complex today than it was 30 years ago, and modern programming languages reflect that.''"<ref>[http://www.research.att.com/~bs/bs_faq.html#big Why is C++ so BIG?]</ref> |
|||
Other criticism stems from what is missing from C++. For example, the current version of Standard C++ provides no language features to create multi-threaded software. These facilities are present in some other languages including [[Java (programming language)|Java]], [[Ada (programming language)|Ada]], and [[C Sharp (programming language)|C#]] (see also [[Lock (computer science)#Language support|Lock]]). It is possible to use operating system calls or third party libraries to do multi-threaded programming, but both approaches may create portability concerns. The new [[C++0x]] standard addresses this matter by extending the language with threading facilities. |
|||
C++ is also sometimes compared unfavorably with languages such as [[Smalltalk (programming language)|Smalltalk]], [[Java (programming language)|Java]], or [[Eiffel (programming language)|Eiffel]] on the basis that it enables programmers to "mix and match" [[object-oriented]] programming, [[procedural programming]], [[generic programming]], [[functional programming]], [[declarative programming]], and others, rather than strictly enforcing a single style, {{Citation needed|date=September 2007}} although this feature may also be considered an advantage. |
|||
A fraudulent article was written wherein Bjarne Stroustrup is supposedly interviewed for a [[1998]] issue of IEEE's 'Computer' magazine<ref> Unattributed. [http://flinflon.brandonu.ca/dueck/1997/62285/stroustroup.html Previously unpublished interview with Bjarne Stroustroup, designer of C++]. <!--accessed January 19, 2010--></ref>. In this article, the interviewer expects to discuss the successes of C++ now that several years had passed after its introduction. Instead, Stroustrup proceeds to confess that his invention of C++ was intended to create the most complex and difficult language possible to weed out amateur programmers and raise the salaries of the few programmers who could master the language. The article contains various criticisms of C++'s complexity and poor usability, most false or exaggerated. In reality, Stroustrup wrote no such article, and due to the pervasiveness of the hoax, was compelled to publish an official denial on his website.<ref> Stroustrup, Bjarne. [http://www2.research.att.com/~bs/bs_faq.html#IEEE Stroustrup FAQ: Did you really give an interview to IEEE?] <!--accessed January 19, 2010--></ref>. |
|||
== See also == |
|||
* ''[[The C++ Programming Language]]'' |
|||
* [[C++0x]], the planned new standard for C++ |
|||
* [[Comparison of integrated development environments#C.2FC.2B.2B|Comparison of integrated development environments for C/C++]] |
|||
* [[Comparison of programming languages]] |
|||
* [[List of compilers#C.2FC.2B.2B compilers|List of C++ compilers]] |
|||
* [[List of C++ template libraries]] |
|||
== References == |
|||
{{reflist|2}} |
|||
== Further reading == |
|||
{{refbegin|2}} |
|||
* {{cite book | first = David | last = Abrahams | authorlink = David Abrahams (computer programmer) | coauthors = [[Aleksey Gurtovoy]] | title = C++ Template Metaprogramming: Concepts, Tools, and Techniques from Boost and Beyond | publisher = Addison-Wesley | isbn = 0-321-22725-5 }} |
|||
* {{cite book | first = Andrei | last = Alexandrescu | authorlink = Andrei Alexandrescu | year = 2001 | title = Modern C++ Design: Generic Programming and Design Patterns Applied | publisher = Addison-Wesley | isbn = 0-201-70431-5 }} |
|||
* {{cite book | first = Pete | last = Becker | authorlink = Pete Becker | year = 2006 | title = The C++ Standard Library Extensions : A Tutorial and Reference | publisher = Addison-Wesley | isbn = 0-321-41299-0 }} |
|||
* {{cite book | first = Andrei | last = Alexandrescu | coauthors = Herb Sutter | authorlink = Andrei Alexandrescu | year = 2004 | title = C++ Design and Coding Standards: Rules and Guidelines for Writing Programs | publisher = Addison-Wesley | isbn = 0-321-11358-6 }} |
|||
* {{cite book | first = James O. | last = Coplien | authorlink = James O. Coplien | year = 1992, reprinted with corrections 1994 | title = Advanced C++: Programming Styles and Idioms | isbn = 0-201-54855-0 }} |
|||
* {{cite book | first = Stephen C. | last = Dewhurst | year = 2005 | title = C++ Common Knowledge: Essential Intermediate Programming | publisher = Addison-Wesley | isbn = 0-321-32192-8 }} |
|||
* {{cite book | author = Information Technology Industry Council | authorlink = Information and Communications Technology Council | |
|||
publisher = ISO/IEC | location = Geneva | title = Programming languages — C++ | id = 14882:2003(E) | edition = Second edition | date = 15 October 2003 }} |
|||
* {{cite book | first = Nicolai M | last = Josuttis | authorlink = Nicolai M. Josuttis | title = The C++ Standard Library | publisher = Addison-Wesley | isbn = 0-201-37926-0 }} |
|||
* {{cite book | first = Andrew | last = Koenig | authorlink = Andrew Koenig (programmer) |
|||
| coauthors = Barbara E. Moo | year = 2000 | title = Accelerated C++ - Practical Programming by Example | publisher = Addison-Wesley | isbn = 0-201-70353-X }} |
|||
* {{cite book | first = Stanley B. | last = Lippman | coauthors = Josée Lajoie, Barbara E. Moo | year = 2005 | title = C++ Primer | publisher = Addison-Wesley | isbn = 0-201-72148-1 }} |
|||
* {{cite book | first = Stanley B. | last = Lippman | year = 1996 | title = Inside the C++ Object Model | publisher = Addison-Wesley | isbn = 0-201-83454-5 }} |
|||
* {{cite book | first = Bjarne | last = Stroustrup | authorlink = Bjarne Stroustrup | year = 2000 | title = The C++ Programming Language | edition = Special Edition | publisher = Addison-Wesley | isbn = 0-201-70073-5 }} |
|||
* {{cite book | first = Bjarne | last = Stroustrup | authorlink = Bjarne Stroustrup | year = 1994 | title = The Design and Evolution of C++ | publisher = Addison-Wesley | isbn = 0-201-54330-3 }} |
|||
* {{cite book | first = Bjarne | last = Stroustrup | authorlink = Bjarne_Stroustrup| title = Programming Principles and Practice Using C++ | publisher = Addison-Wesley | isbn = 0321543726}} |
|||
* {{cite book | first = Herb | last = Sutter | authorlink = Herb Sutter | |
|||
year = 2001 | title = More Exceptional C++: 40 New Engineering Puzzles, Programming Problems, and Solutions | publisher = Addison-Wesley | isbn = 0-201-70434-X }} |
|||
* {{cite book | first = Herb | last = Sutter | authorlink = Herb Sutter | |
|||
year = 2004 | title = Exceptional C++ Style | publisher = Addison-Wesley | isbn = 0-201-76042-8 }} |
|||
* {{cite book | first = David | last = Vandevoorde | authorlink = David Vandevoorde | coauthors = [[Nicolai M. Josuttis]] | year = 2003 | title = C++ Templates: The complete Guide | publisher = Addison-Wesley | isbn = 0-201-73484-2 }} |
|||
*[[Scott Meyers]] (2005). ''Effective C++''. Third Edition. Addison-Wesley. ISBN 0-321-33487-6 |
|||
{{refend}} |
|||
==External links== |
|||
{{Wikibooks|C++}} |
|||
{{Wiktionary}} |
|||
{{Wikiversity}} |
|||
* [http://www.open-std.org/jtc1/sc22/wg21/ JTC1/SC22/WG21] - The ISO/IEC C++ Standard Working Group |
|||
** [http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2010/n3035.pdf n3035.pdf] – Latest draft of ''ISO/IEC 14882 – Programming Language C++'' (16 February 2010) |
|||
* [http://www.research.att.com/~bs/hopl2.pdf A paper by Stroustrup showing the timeline of C++ evolution (1979-1991)] |
|||
* [http://www.research.att.com/~bs/bs_faq2.html Bjarne Stroustrup's C++ Style and Technique FAQ] |
|||
* [http://incubator.apache.org/stdcxx/doc Apache C++ Standard Library Documentation] |
|||
* [http://www.parashift.com/c%2B%2B-faq-lite/ C++ FAQ Lite by Marshall Cline] |
|||
* [http://www.computerworld.com.au/index.php/id;408408016;pp;1;fp;16;fpid;1 Computer World interview with Bjarne Stroustrup] |
|||
* [http://www.crazyengineers.com/small-talk/1-cover-story/24-small-talk-with-dr-bjarne-stroustrup CrazyEngineers.com interview with Bjarne Stroustrup] |
|||
* [http://www.devx.com/SpecialReports/Article/38813/0/page/1 The State of the Language: An Interview with Bjarne Stroustrup (August 15, 2008)] |
|||
{{Integrated development environments for C and C++|state=uncollapsed}} |
|||
{{ISO standards}} |
|||
{{DEFAULTSORT:C++}} |
|||
[[Category:C++]] |
|||
[[Category:Class-based programming languages]] |
|||
[[Category:C programming language family]] |
|||
[[Category:Object-oriented programming languages]] |
|||
[[Category:Curly bracket programming languages]] |
|||
[[Category:Programming languages created in 1983]] |
|||
[[Category:Cross-platform software]] |
|||
[[Category:Algol programming language family]] |
|||
[[af:C++]] |
|||
[[ar:سي++ (لغة برمجة)]] |
|||
[[an:C++]] |
|||
[[az:C++]] |
|||
[[bn:সি++]] |
|||
[[be:C++]] |
|||
[[bs:C++]] |
|||
[[br:Areg C++]] |
|||
[[bg:C++]] |
|||
[[ca:C++]] |
|||
[[cv:Си++]] |
|||
[[cs:C++]] |
|||
[[da:C++]] |
|||
[[de:C++]] |
|||
[[et:C++]] |
|||
[[el:C++]] |
|||
[[es:C++]] |
|||
[[eo:C++]] |
|||
[[eu:C++]] |
|||
[[fa:سی++]] |
|||
[[fr:C++]] |
|||
[[ga:C++]] |
|||
[[gl:C++]] |
|||
[[gan:C++]] |
|||
[[ko:C++]] |
|||
[[hy:C++]] |
|||
[[hi:सी++]] |
|||
[[hr:C++]] |
|||
[[id:C++]] |
|||
[[ia:C++]] |
|||
[[is:C++]] |
|||
[[it:C++]] |
|||
[[he:C++]] |
|||
[[ka:C++]] |
|||
[[la:C++]] |
|||
[[lv:C++]] |
|||
[[lb:C++]] |
|||
[[lt:C++]] |
|||
[[hu:C++]] |
|||
[[mk:C++]] |
|||
[[ml:സി++]] |
|||
[[mr:सी प्लस प्लस प्रोग्रॅमिंग लँग्वेज]] |
|||
[[ms:C++]] |
|||
[[my:C++]] |
|||
[[nl:C++]] |
|||
[[new:सी++]] |
|||
[[ja:C++]] |
|||
[[no:C++]] |
|||
[[nn:C++]] |
|||
[[oc:C++]] |
|||
[[uz:C++]] |
|||
[[pl:C++]] |
|||
[[pt:C++]] |
|||
[[kaa:C++]] |
|||
[[ro:C++]] |
|||
[[ru:C++]] |
|||
[[sah:C++]] |
|||
[[sq:C++]] |
|||
[[simple:C++]] |
|||
[[sk:C++]] |
|||
[[sl:C++]] |
|||
[[sr:C++]] |
|||
[[sh:C++]] |
|||
[[fi:C++]] |
|||
[[sv:C++]] |
|||
[[ta:சி++]] |
|||
[[te:సీ ప్లస్ ప్లస్]] |
|||
[[th:ภาษาซีพลัสพลัส]] |
|||
[[tg:C++]] |
|||
[[tr:C++]] |
|||
[[tk:C++ programmirleme]] |
|||
[[bug:C++]] |
|||
[[uk:C++]] |
|||
[[vi:C++]] |
|||
[[zh-yue:C++]] |
|||
[[bat-smg:C++]] |
|||
[[zh:C++]] |
Revision as of 15:06, 25 March 2010
File:C plus plus book.jpg | |
Paradigm | Multi-paradigm: procedural, object-oriented, generic |
---|---|
Designed by | Bjarne Stroustrup |
Developer | Bjarne Stroustrup Bell Labs ISO/IEC JTC1/SC22/WG21 |
First appeared | 1983 |
Preview release | |
Typing discipline | Static, unsafe, nominative |
OS | Cross-platform (multi-platform) |
Filename extensions | .hh .hpp .hxx .h++ .cc .cpp .cxx .c++ |
Website | isocpp |
Major implementations | |
Borland C++ Builder, GCC, Intel C++ Compiler, Microsoft Visual C++, Sun Studio, Turbo C++, Comeau C/C++ | |
Dialects | |
ISO/IEC C++ 1998, ISO/IEC C++ 2003 | |
Influenced by | |
C, Simula, Ada 83, ALGOL 68, CLU, ML[1] | |
Influenced | |
Perl, Lua, Ada 95, Java, PHP, D, C99, C#, Aikido, Falcon, Dao |
C++ (pronounced "see plus plus") is a statically typed, free-form, multi-paradigm, compiled, general-purpose programming language. It is regarded as a middle-level language, as it comprises a combination of both high-level and low-level language features.[2] It was developed by Bjarne Stroustrup starting in 1979 at Bell Labs as an enhancement to the C programming language and originally named "C with Classes". It was renamed C++ in 1983.[3]
As one of the most popular programming languages ever created,[4][5] C++ is widely used in the software industry. Some of its application domains include systems software, application software, device drivers, embedded software, high-performance server and client applications, and entertainment software such as video games. Several groups provide both free and proprietary C++ compiler software, including the GNU Project, Microsoft, Intel and Borland. C++ has greatly influenced many other popular programming languages, most notably Java.
C++ is also used for hardware design, where design is initially described in C++, then analyzed, architecturally constrained, and scheduled to create a register transfer level hardware description language via high-level synthesis.
The language began as enhancements to C, first adding classes, then virtual functions, operator overloading, multiple inheritance, templates, and exception handling among other features. After years of development, the C++ programming language standard was ratified in 1998 as ISO/IEC 14882:1998. That standard is still current, but is amended by the 2003 technical corrigendum, ISO/IEC 14882:2003. The next standard version (known informally as C++0x) is in development.
History
Stroustrup began work on "C with Classes" in 1979. The idea of creating a new language originated from Stroustrup's experience in programming for his Ph.D. thesis. Stroustrup found that Simula had features that were very helpful for large software development, but the language was too slow for practical use, while BCPL was fast but too low-level to be suitable for large software development. When Stroustrup started working in AT&T Bell Labs, he had the problem of analyzing the UNIX kernel with respect to distributed computing. Remembering his Ph.D. experience, Stroustrup set out to enhance the C language with Simula-like features. C was chosen because it was general-purpose, fast, portable and widely used. Besides C and Simula, some other languages that inspired him were ALGOL 68, Ada, CLU and ML. At first, the class, derived class, strong type checking, inlining, and default argument features were added to C via Stroustrup's C++ to C compiler, Cfront. The first commercial implementation of C++ was released in October 1985.[6]
In 1983, the name of the language was changed from C with Classes to C++ (++ being the increment operator in C and C++). New features were added including virtual functions, function name and operator overloading, references, constants, user-controlled free-store memory control, improved type checking, and BCPL style single-line comments with two forward slashes (//). In 1985, the first edition of The C++ Programming Language was released, providing an important reference to the language, since there was not yet an official standard. Release 2.0 of C++ came in 1989. New features included multiple inheritance, abstract classes, static member functions, const member functions, and protected members. In 1990, The Annotated C++ Reference Manual was published. This work became the basis for the future standard. Late addition of features included templates, exceptions, namespaces, new casts, and a Boolean type.
As the C++ language evolved, a standard library also evolved with it. The first addition to the C++ standard library was the stream I/O library which provided facilities to replace the traditional C functions such as printf and scanf. Later, among the most significant additions to the standard library, was the Standard Template Library.
C++ continues to be used and is one of the preferred programming languages to develop professional applications. The popularity of the language continues to grow.[7]
Language standard
In 1998, the C++ standards committee (the ISO/IEC JTC1/SC22/WG21 working group) standardized C++ and published the international standard ISO/IEC 14882:1998 (informally known as C++98[8]). For some years after the official release of the standard, the committee processed defect reports, and published a corrected version of the C++ standard, ISO/IEC 14882:2003, in 2003. In 2005, a technical report, called the "Library Technical Report 1" (often known as TR1 for short), was released. While not an official part of the standard, it specified a number of extensions to the standard library, which were expected to be included in the next version of C++. Support for TR1 is growing in almost all currently maintained C++ compilers.
The standard for the next version of the language (known informally as C++0x) is in development.
Etymology
According to Stroustrup: "the name signifies the evolutionary nature of the changes from C".[9] During C++'s development period, the language had been referred to as "new C", then "C with Classes". The final name is credited to Rick Mascitti (mid-1983) and was first used in December 1983. When Mascitti was questioned informally in 1992 about the naming, he indicated that it was given in a tongue-in-cheek spirit. It stems from C's "++" operator (which increments the value of a variable) and a common naming convention of using "+" to indicate an enhanced computer program. There is no language called "C plus". ABCL/c+ was the name of an earlier, unrelated programming language.
Philosophy
In The Design and Evolution of C++ (1994), Bjarne Stroustrup describes some rules that he used for the design of C++:
- C++ is designed to be a statically typed, general-purpose language that is as efficient and portable as C
- C++ is designed to directly and comprehensively support multiple programming styles (procedural programming, data abstraction, object-oriented programming, and generic programming)
- C++ is designed to give the programmer choice, even if this makes it possible for the programmer to choose incorrectly
- C++ is designed to be as compatible with C as possible, therefore providing a smooth transition from C
- C++ avoids features that are platform specific or not general purpose
- C++ does not incur overhead for features that are not used (the "zero-overhead principle")
- C++ is designed to function without a sophisticated programming environment
Stroustrup also mentions that C++ was always intended to make programming more fun and that many of the double meanings in the language are intentional.
Inside the C++ Object Model (Lippman, 1996) describes how compilers may convert C++ program statements into an in-memory layout. Compiler authors are, however, free to implement the standard in their own manner.
Standard library
The 1998 ANSI/ISO C++ standard consists of two parts: the core language and the C++ Standard Library; the latter includes most of the Standard Template Library (STL) and a slightly modified version of the C standard library. Many C++ libraries exist which are not part of the standard, and, using linkage specification, libraries can even be written in languages such as C, Fortran, Pascal, or BASIC. Which of these are supported is compiler dependent.
The C++ standard library incorporates the C standard library with some small modifications to make it optimized with the C++ language. Another large part of the C++ library is based on the STL. This provides such useful tools as containers (for example vectors and lists), iterators to provide these containers with array-like access and algorithms to perform operations such as searching and sorting. Furthermore (multi)maps (associative arrays) and (multi)sets are provided, all of which export compatible interfaces. Therefore it is possible, using templates, to write generic algorithms that work with any container or on any sequence defined by iterators. As in C, the features of the library are accessed by using the #include
directive to include a standard header. C++ provides 69 standard headers, of which 19 are deprecated.
The STL was originally a third-party library from HP and later SGI, before its incorporation into the C++ standard. The standard does not refer to it as "STL", as it is merely a part of the standard library, but many people still use that term to distinguish it from the rest of the library (input/output streams, internationalization, diagnostics, the C library subset, etc.).
Most C++ compilers provide an implementation of the C++ standard library, including the STL. Compiler-independent implementations of the STL, such as STLPort,[10] also exist. Other projects also produce various custom implementations of the C++ standard library and the STL with various design goals.
Language features
C++ inherits most of C's syntax and the C preprocessor. The following is Bjarne Stroustrup's version of the Hello world program which uses the C++ standard library stream facility to write a message to standard output:[11][12]
#include <iostream>
int main()
{
std::cout << "Hello, world!\n";
}
The C++ standard requires the main function to be defined with int
as its return type, but it need not return a value with an explicit return statement, as an implicit return 0
is executed when the end of main
is reached.[13] Such an implicit <return> rule does not apply to any other value-returning functions: If control reaches their closing }
undefined behavior results.[14]
Operators and operator overloading
C++ provides more than 30 operators, covering basic arithmetic, bit manipulation, indirection, comparisons, logical operations and others. Almost all operators can be overloaded for user-defined types, with a few notable exceptions such as member access (. and .*). The rich set of overloadable operators is central to using C++ as a domain specific language. The overloadable operators are also an essential part of many advanced C++ programming techniques, such as smart pointers. Overloading an operator does not change the precedence of calculations involving the operator, nor does it change the number of operands that the operator uses (any operand may however be ignored by the operator, though it will be evaluated prior to execution).
Templates
C++ templates enable generic programming. C++ supports both function and class templates. Templates may be parameterized by types, compile-time constants, and other templates. C++ templates are implemented by instantiation at compile-time. To instantiate a template, compilers substitute specific arguments for a template's parameters to generate a concrete function or class instance. Some substitutions are not possible; these are eliminated by an overload resolution policy described by the phrase "Substitution failure is not an error" (SFINAE). Templates are a powerful tool that can be used for generic programming, template metaprogramming, and code optimization, but this power implies a cost. Template use may increase code size, since each template instantiation produces a copy of the template code: one for each set of template arguments. This is in contrast to run-time generics seen in other languages (e.g. Java) where at compile-time the type is erased and a single template body is preserved.
Templates are different from macros: while both of these compile-time language features enable conditional compilation, templates are not restricted to lexical substitution. Templates are aware of the semantics and type system of their companion language, as well as all compile-time type definitions, and can perform high-level operations including programmatic flow control based on evaluation of strictly type-checked parameters. Macros are capable of conditional control over compilation based on predetermined criteria, but cannot instantiate new types, recurse, or perform type evaluation and in effect are limited to pre-compilation text-substitution and text-inclusion/exclusion. In other words, macros can control compilation flow based on pre-defined symbols but cannot, unlike templates, independently instantiate new symbols. Templates are a tool for static polymorphism (see below) and generic programming.
In addition, templates are a compile time mechanism in C++ which is Turing-complete, meaning that any computation expressible by a computer program can be computed, in some form, by a template metaprogram prior to runtime.
In summary, a template is a compile-time parameterized function or class written without knowledge of the specific arguments used to instantiate it. After instantiation the resulting code is equivalent to code written specifically for the passed arguments. In this manner, templates provide a way to decouple generic, broadly-applicable aspects of functions and classes (encoded in templates) from specific aspects (encoded in template parameters) without sacrificing performance due to abstraction.
Objects
C++ introduces object-oriented (OO) features to C. It offers classes, which provide the four features commonly present in OO (and some non-OO) languages: abstraction, encapsulation, inheritance, and polymorphism. Objects are instances of classes created at runtime. The class can be thought of as a template from which many different individual objects may be generated as a program runs.
Encapsulation
Encapsulation is the hiding of information in order to ensure that data structures and operators are used as intended and to make the usage model more obvious to the developer. C++ provides the ability to define classes and functions as its primary encapsulation mechanisms. Within a class, members can be declared as either public, protected, or private in order to explicitly enforce encapsulation. A public member of the class is accessible to any function. A private member is accessible only to functions that are members of that class and to functions and classes explicitly granted access permission by the class ("friends"). A protected member is accessible to members of classes that inherit from the class in addition to the class itself and any friends.
The OO principle is that all of the functions (and only the functions) that access the internal representation of a type should be encapsulated within the type definition. C++ supports this (via member functions and friend functions), but does not enforce it: the programmer can declare parts or all of the representation of a type to be public, and is allowed to make public entities that are not part of the representation of the type. Because of this, C++ supports not just OO programming, but other weaker decomposition paradigms, like modular programming.
It is generally considered good practice to make all data private or protected, and to make public only those functions that are part of a minimal interface for users of the class. This hides all the details of data implementation, allowing the designer to later fundamentally change the implementation without changing the interface in any way.[15][16]
Inheritance
Inheritance allows one data type to acquire properties of other data types. Inheritance from a base class may be declared as public, protected, or private. This access specifier determines whether unrelated and derived classes can access the inherited public and protected members of the base class. Only public inheritance corresponds to what is usually meant by "inheritance". The other two forms are much less frequently used. If the access specifier is omitted, a "class" inherits privately, while a "struct" inherits publicly. Base classes may be declared as virtual; this is called virtual inheritance. Virtual inheritance ensures that only one instance of a base class exists in the inheritance graph, avoiding some of the ambiguity problems of multiple inheritance.
Multiple inheritance is a C++ feature sometimes considered controversial. Multiple inheritance allows a class to be derived from more than one base class; this can result in a complicated graph of inheritance relationships. For example, a "Flying Cat" class can inherit from both "Cat" and "Flying Mammal". Some other languages, such as Java or C#, accomplish something similar (although more limited) by allowing inheritance of multiple interfaces while restricting the number of base classes to one (interfaces, unlike classes, provide only declarations of member functions, no implementation or member data). Interfaces and abstract classes in Java and C# can be defined in C++ as a class containing only pure virtual functions, often known as an abstract base class or "ABC." Programmers preferring the Java/C# model of inheritance can choose to inherit only one non-abstract class, although in this case the declared member functions of the abstract base classes must be explicitly defined and cannot be inherited.
Polymorphism
Polymorphism enables one common interface for many implementations, and for objects to act differently under different circumstances.
C++ supports several kinds of static (compile-time) and dynamic (run-time) polymorphisms. Compile-time polymorphism does not allow for certain run-time decisions, while run-time polymorphism typically incurs a performance penalty.
Static polymorphism
Function overloading allows programs to declare multiple functions having the same name (but with different arguments). The functions are distinguished by the number and/or types of their formal parameters. Thus, the same function name can refer to different functions depending on the context in which it is used. The type returned by the function is not used to distinguish overloaded functions.
When declaring a function, a programmer can specify default arguments for one or more parameters. Doing so allows the parameters with defaults to optionally be omitted when the function is called, in which case the default arguments will be used. When a function is called with fewer arguments than there are declared parameters, explicit arguments are matched to parameters in left-to-right order, with any unmatched parameters at the end of the parameter list being assigned their default arguments. In many cases, specifying default arguments in a single function declaration is preferable to providing overloaded function definitions with different numbers of parameters.
Templates in C++ provide a sophisticated mechanism for writing generic, polymorphic code. In particular, through the Curiously Recurring Template Pattern it's possible to implement a form of static polymorphism that closely mimics the syntax for overriding virtual functions. Since C++ templates are type-aware and Turing-complete they can also be used to let the compiler resolve recursive conditionals and generate substantial programs through template metaprogramming.
Dynamic polymorphism
Inheritance
Variable pointers (and references) to a base class type in C++ can refer to objects of any derived classes of that type in addition to objects exactly matching the variable type. This allows arrays and other kinds of containers to hold pointers to objects of differing types. Because assignment of values to variables usually occurs at run-time, this is necessarily a run-time phenomenon.
C++ also provides a dynamic_cast
operator, which allows the program to safely attempt conversion of an object into an object of a more specific object type (as opposed to conversion to a more general type, which is always allowed). This feature relies on run-time type information (RTTI). Objects known to be of a certain specific type can also be cast to that type with static_cast
, a purely compile-time construct which is faster and does not require RTTI.
Virtual member functions
Ordinarily when a function in a derived class overrides a function in a base class, the function to call is determined by the type of the object. A given function is overridden when there exists no difference, in the number or type of parameters, between two or more definitions of that function. Hence, at compile time it may not be possible to determine the type of the object and therefore the correct function to call, given only a base class pointer; the decision is therefore put off until runtime. This is called dynamic dispatch. Virtual member functions or methods[17] allow the most specific implementation of the function to be called, according to the actual run-time type of the object. In C++, this is commonly done using virtual function tables. If the object type is known, this may be bypassed by prepending a fully qualified class name before the function call, but in general calls to virtual functions are resolved at run time.
In addition to standard member functions, operator overloads and destructors can be virtual. A general rule of thumb is that if any functions in the class are virtual, the destructor should be as well. As the type of an object at its creation is known at compile time, constructors, and by extension copy constructors, cannot be virtual. Nonetheless a situation may arise where a copy of an object needs to be created when a pointer to a derived object is passed as a pointer to a base object. In such a case a common solution is to create a clone()
(or similar) function and declare that as virtual. The clone()
method creates and returns a copy of the derived class when called.
A member function can also be made "pure virtual" by appending it with = 0
after the closing parenthesis and before the semicolon. Objects cannot be created of a class with a pure virtual function and are called abstract data types. Such abstract data types can only be derived from. Any derived class inherits the virtual function as pure and must provide a non-pure definition of it (and all other pure virtual functions) before objects of the derived class can be created. A program that attempts to create an object of a class with a pure virtual member function or inherited pure virtual member function is ill-formed.
Parsing and processing C++ source code
It is relatively difficult to write a good C++ parser with classic parsing algorithms such as LALR(1).[18] This is partly because the C++ grammar is not LALR. Because of this, there are very few tools for analyzing or performing non-trivial transformations (e.g., refactoring) of existing code. One way to handle this difficulty is to choose a different syntax, such as Significantly Prettier and Easier C++ Syntax, which is LALR(1) parsable. More powerful parsers, such as GLR parsers, can be substantially simpler (though slower).
Parsing (in the literal sense of producing a syntax tree) is not the most difficult problem in building a C++ processing tool. Such tools must also have the same understanding of the meaning of the identifiers in the program as a compiler might have. Practical systems for processing C++ must then not only parse the source text, but be able to resolve for each identifier precisely which definition applies (e.g. they must correctly handle C++'s complex scoping rules) and what its type is, as well as the types of larger expressions.
Finally, a practical C++ processing tool must be able to handle the variety of C++ dialects used in practice (such as that supported by the GNU Compiler Collection and that of Microsoft's Visual C++) and implement appropriate analyzers, source code transformers, and regenerate source text. Combining advanced parsing algorithms such as GLR with symbol table construction and program transformation machinery can enable the construction of arbitrary C++ tools. [citation needed]
Compatibility
Producing a reasonably standards-compliant C++ compiler has proven to be a difficult task for compiler vendors in general. For many years, different C++ compilers implemented the C++ language to different levels of compliance to the standard, and their implementations varied widely in some areas such as partial template specialization. Recent releases of most popular C++ compilers support almost all of the C++ 1998 standard.[19]
One particular point of contention is the export keyword, intended to allow template definitions to be separated from their declarations. The first compiler to implement export was Comeau C/C++, in early 2003 (5 years after the release of the standard); in 2004, the beta compiler of Borland C++ Builder X was also released with export. Both of these compilers are based on the EDG C++ front end. Other compilers such as GCC do not support it at all. Many C++ books[which?] (such as Beginning ANSI C++ by Ivor Horton) provide example code with the keyword that will not compile in most compilers, without reference to this problem. Herb Sutter, former convener of the C++ standards committee, recommended that export be removed from future versions of the C++ standard,[20] but finally the decision was made to retain it.[21]
In order to give compiler vendors greater freedom, the C++ standards committee decided not to dictate the implementation of name mangling, exception handling, and other implementation-specific features. The downside of this decision is that object code produced by different compilers is expected to be incompatible. There are, however, third party standards for particular machines or operating systems which attempt to standardize compilers on those platforms (for example C++ ABI[22]); some compilers adopt a secondary standard for these items.
With C
C++ is often considered to be a superset of C, but this is not strictly true.[23] Most C code can easily be made to compile correctly in C++, but there are a few differences that cause some valid C code to be invalid in C++, or to behave differently in C++.
One commonly encountered difference is that C allows implicit conversion from void*
to other pointer types, but C++ does not. Another common portability issue is that C++ defines many new keywords, such as new
and class
, that may be used as identifiers (e.g. variable names) in a C program.
Some incompatibilities have been removed by the latest (C99) C standard, which now supports C++ features such as //
comments and mixed declarations and code. On the other hand, C99 introduced a number of new features that C++ does not support, such as variable-length arrays, native complex-number types, designated initializers and compound literals.[24] However, at least some of the new C99 features will likely be included in the next version of the C++ standard, C++0x.
In order to intermix C and C++ code, any function declaration or definition that is to be called from/used both in C and C++ must be declared with C linkage by placing it within an extern "C" {/*...*/}
block. Such a function may not rely on features depending on name mangling (i.e., function overloading).
Criticism
Critics of the language raise several points. First, since C++ includes C as a subset, it inherits many of the criticisms leveled at C. For its large feature set, it is criticized as being "bloated", over-complicated, and difficult to fully master.[25] Bjarne Stroustrup points out that resultant executables do not support these claims of bloat: "I have even seen the C++ version of the 'hello world' program smaller than the C version."[26] An Embedded C++ standard was proposed to deal with part of this, but criticized for leaving out useful parts of the language that incur no runtime penalty.[27]
C++ is more complex than some other programming languages. The ISO standard of the C++ language is about 310 pages (excluding the definitions of what is in the library). For comparison, the C programming language standard, written eight years earlier, is about 160 pages, and C#'s ECMA language definition document is about 440 pages. Bjarne Stroustrup points out that "The programming world is far more complex today than it was 30 years ago, and modern programming languages reflect that."[28]
Other criticism stems from what is missing from C++. For example, the current version of Standard C++ provides no language features to create multi-threaded software. These facilities are present in some other languages including Java, Ada, and C# (see also Lock). It is possible to use operating system calls or third party libraries to do multi-threaded programming, but both approaches may create portability concerns. The new C++0x standard addresses this matter by extending the language with threading facilities.
C++ is also sometimes compared unfavorably with languages such as Smalltalk, Java, or Eiffel on the basis that it enables programmers to "mix and match" object-oriented programming, procedural programming, generic programming, functional programming, declarative programming, and others, rather than strictly enforcing a single style, [citation needed] although this feature may also be considered an advantage.
A fraudulent article was written wherein Bjarne Stroustrup is supposedly interviewed for a 1998 issue of IEEE's 'Computer' magazine[29]. In this article, the interviewer expects to discuss the successes of C++ now that several years had passed after its introduction. Instead, Stroustrup proceeds to confess that his invention of C++ was intended to create the most complex and difficult language possible to weed out amateur programmers and raise the salaries of the few programmers who could master the language. The article contains various criticisms of C++'s complexity and poor usability, most false or exaggerated. In reality, Stroustrup wrote no such article, and due to the pervasiveness of the hoax, was compelled to publish an official denial on his website.[30].
See also
- The C++ Programming Language
- C++0x, the planned new standard for C++
- Comparison of integrated development environments for C/C++
- Comparison of programming languages
- List of C++ compilers
- List of C++ template libraries
References
- ^ Stroustrup, Bjarne (1997). "1". The C++ Programming Language (Third ed.). ISBN 0201889544. OCLC 59193992.
{{cite book}}
:|access-date=
requires|url=
(help) - ^ C++ The Complete Reference Third Edition, Herbert Schildt, Publisher: Osborne McGraw-Hill.
- ^ ATT.com
- ^ "Programming Language Popularity". 2009. Retrieved 2009-01-16.
- ^ "TIOBE Programming Community Index". 2009. Retrieved 2009-05-06.
- ^ "Bjarne Stroustrup's FAQ — When was C++ invented?". Retrieved 30 May 2006.
- ^ "Trends on C++ Programmers, Developers & Engineers". Retrieved 1 December 2008.
- ^ Stroustrup, Bjarne. "C++ Glossary". Retrieved 8 June 2007.
- ^ "Bjarne Stroustrup's FAQ — Where did the name "C++" come from?". Retrieved 16 January 2008.
- ^ STLPort home page, quote from "The C++ Standard Library" by Nicolai M. Josuttis, p138., ISBN 0-201 37926-0, Addison-Wesley, 1999: "An exemplary version of STL is the STLport, which is available for free for any platform"
- ^ Stroustrup, Bjarne (2000). The C++ Programming Language (Special Edition ed.). Addison-Wesley. p. 46. ISBN 0-201-70073-5.
{{cite book}}
:|edition=
has extra text (help) - ^ Open issues for The C++ Programming Language (3rd Edition) - This code is copied directly from Bjarne Stroustrup's errata page (p. 633). He addresses the use of
'\n'
rather thanstd::endl
. Also see www.research.att.com for an explanation of the implicitreturn 0;
in themain
function. This implicit return is not available in other functions. - ^ ISO/IEC (2003). ISO/IEC 14882:2003(E): Programming Languages - C++ §3.6.1 Main function [basic.start.main] para. 5
- ^ ISO/IEC (2003). ISO/IEC 14882:2003(E): Programming Languages - C++ §6.6.3 The return statement [stmt.return] para. 2
- ^ Sutter, Herb; Alexandrescu, Andrei (2004). C++ Coding Standards: 101 Rules, Guidelines, and Best Practices. Addison-Wesley.
- ^ Henricson, Mats; Nyquist, Erik (1997). Industrial Strength C++. Prentice Hall. ISBN ISBN 0-13-120965-5.
{{cite book}}
: Check|isbn=
value: invalid character (help) - ^ Stroustrup, Bjarne (2000). The C++ Programming Language (Special Edition ed.). Addison-Wesley. p. 310. ISBN 0-201-70073-5.
A virtual member function is sometimes called a method.
{{cite book}}
:|edition=
has extra text (help) - ^ Andrew Birkett. "Parsing C++ at nobugs.org". Nobugs.org. Retrieved 3 July 2009.
- ^ Herb Sutter (15 April 2003). "C++ Conformance Roundup". Dr. Dobb's Journal. Retrieved 30 May 2006.
- ^ Template:PDFlink
- ^ "Minutes of J16 Meeting No. 36/WG21 Meeting No. 31, April 7-11, 2003". 25 April 2003. Retrieved 4 September 2006.
- ^ "C++ ABI". Retrieved 30 May 2006.
- ^ "Bjarne Stroustrup's FAQ - Is C a subset of C++?". Retrieved 18 January 2008.
- ^ "C9X -- The New C Standard". Retrieved 27 December 2008.
- ^ Morris, Richard (July 2, 2009). "Niklaus Wirth: Geek of the Week". Retrieved 8 August 2009.
C++ is a language that was designed to cater to everybody's perceived needs. As a result, the language and even more so its implementations have become complex and bulky, difficult to understand, and likely to contain errors for ever.
- ^ Why is the code generated for the "Hello world" program ten times larger for C++ than for C?
- ^ What do you think of EC++?
- ^ Why is C++ so BIG?
- ^ Unattributed. Previously unpublished interview with Bjarne Stroustroup, designer of C++.
- ^ Stroustrup, Bjarne. Stroustrup FAQ: Did you really give an interview to IEEE?
Further reading
- Abrahams, David. C++ Template Metaprogramming: Concepts, Tools, and Techniques from Boost and Beyond. Addison-Wesley. ISBN 0-321-22725-5.
{{cite book}}
: Unknown parameter|coauthors=
ignored (|author=
suggested) (help) - Alexandrescu, Andrei (2001). Modern C++ Design: Generic Programming and Design Patterns Applied. Addison-Wesley. ISBN 0-201-70431-5.
- Becker, Pete (2006). The C++ Standard Library Extensions : A Tutorial and Reference. Addison-Wesley. ISBN 0-321-41299-0.
- Alexandrescu, Andrei (2004). C++ Design and Coding Standards: Rules and Guidelines for Writing Programs. Addison-Wesley. ISBN 0-321-11358-6.
{{cite book}}
: Unknown parameter|coauthors=
ignored (|author=
suggested) (help) - Coplien, James O. (1992, reprinted with corrections 1994). Advanced C++: Programming Styles and Idioms. ISBN 0-201-54855-0.
{{cite book}}
: Check date values in:|year=
(help)CS1 maint: year (link) - Dewhurst, Stephen C. (2005). C++ Common Knowledge: Essential Intermediate Programming. Addison-Wesley. ISBN 0-321-32192-8.
- Information Technology Industry Council (15 October 2003). Programming languages — C++ (Second edition ed.). Geneva: ISO/IEC. 14882:2003(E).
{{cite book}}
:|edition=
has extra text (help) - Josuttis, Nicolai M. The C++ Standard Library. Addison-Wesley. ISBN 0-201-37926-0.
- Koenig, Andrew (2000). Accelerated C++ - Practical Programming by Example. Addison-Wesley. ISBN 0-201-70353-X.
{{cite book}}
: Unknown parameter|coauthors=
ignored (|author=
suggested) (help) - Lippman, Stanley B. (2005). C++ Primer. Addison-Wesley. ISBN 0-201-72148-1.
{{cite book}}
: Unknown parameter|coauthors=
ignored (|author=
suggested) (help) - Lippman, Stanley B. (1996). Inside the C++ Object Model. Addison-Wesley. ISBN 0-201-83454-5.
- Stroustrup, Bjarne (2000). The C++ Programming Language (Special Edition ed.). Addison-Wesley. ISBN 0-201-70073-5.
{{cite book}}
:|edition=
has extra text (help) - Stroustrup, Bjarne (1994). The Design and Evolution of C++. Addison-Wesley. ISBN 0-201-54330-3.
- Stroustrup, Bjarne. Programming Principles and Practice Using C++. Addison-Wesley. ISBN 0321543726.
- Sutter, Herb (2001). More Exceptional C++: 40 New Engineering Puzzles, Programming Problems, and Solutions. Addison-Wesley. ISBN 0-201-70434-X.
- Sutter, Herb (2004). Exceptional C++ Style. Addison-Wesley. ISBN 0-201-76042-8.
- Vandevoorde, David (2003). C++ Templates: The complete Guide. Addison-Wesley. ISBN 0-201-73484-2.
{{cite book}}
: Unknown parameter|coauthors=
ignored (|author=
suggested) (help) - Scott Meyers (2005). Effective C++. Third Edition. Addison-Wesley. ISBN 0-321-33487-6
External links
- JTC1/SC22/WG21 - The ISO/IEC C++ Standard Working Group
- n3035.pdf – Latest draft of ISO/IEC 14882 – Programming Language C++ (16 February 2010)
- A paper by Stroustrup showing the timeline of C++ evolution (1979-1991)
- Bjarne Stroustrup's C++ Style and Technique FAQ
- Apache C++ Standard Library Documentation
- C++ FAQ Lite by Marshall Cline
- Computer World interview with Bjarne Stroustrup
- CrazyEngineers.com interview with Bjarne Stroustrup
- The State of the Language: An Interview with Bjarne Stroustrup (August 15, 2008)