Jump to content

C++

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by Mthinkcpp (talk | contribs) at 15:30, 26 June 2014 (Memory management). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

C++
ParadigmMulti-paradigm:[1] procedural, functional, object-oriented, generic
Designed byBjarne Stroustrup
First appeared1983
Stable release
ISO/IEC 14882:2011 / 2011
Preview release
C++14 / 2014
Typing disciplineStatic, Nominative
Implementation languageC++
OSCross-platform (multi-platform)
Filename extensions.cc .cpp .cxx .c++ .h .hh .hpp .hxx .h++
WebsiteNews, status & discussion about Standard C++
Major implementations
LLVM Clang, GCC, Microsoft Visual C++, Intel C++ Compiler
Influenced by
C, Simula, ALGOL 68, Ada, CLU, ML
Influenced
Perl, LPC, Lua, Pike, Ada 95, Java, PHP, D, C99, C#,[2] Falcon, Seed7

C++ (pronounced cee plus plus) is a general purpose programming language. It has imperative, object-oriented and generic programming features, while also providing the facilities for low level memory manipulation.

It is designed with a bias for systems programming (e.g. embedded systems, operating system kernels), with performance, efficiency and flexibility of use as its design requirements. C++ has also been found useful in many other contexts, including desktop applications, servers (e.g. e-commerce, web search, SQL), performance critical applications (e.g. telephone switches, space probes) and entertainment software, such as video games.[3]

It is a compiled language, with implementations of it available on many platforms. Various organizations provide them, including the FSF, LLVM, Microsoft and Intel.

C++ is standardised by the International Organization for Standardization (ISO), which the latest (and current) having being ratified and published by ISO in September 2011 as ISO/IEC 14882:2011 (informally known as C++11).[4] The C++ programming language was initially standardised in 1998 as ISO/IEC 14882:1998, which was then amended by the C++03, ISO/IEC 14882:2003, standard. The current standard (C++11) supersedes these, with new features and an enlarged standard library.

Before standardization (1989 onwards), C++ was developed by Bjarne Stroustrup at Bell Labs, starting in 1979, who wanted an efficient flexible language (like C) that also provided high level features for programme organization.

Many other programming languages have been influenced by C++, including C#, Java and newer versions of C (after 1998).

History

Bjarne Stroustrup, creator of C++

Bjarne Stroustrup, a Danish and British trained computer scientist, began his work on C++'s predecessor "C with Classes" in 1979.[5] The motivation for 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.[6] C was chosen because it was general-purpose, fast, portable and widely used. As well as C and Simula's influences, other languages also influenced C++, including, ALGOL 68, Ada, CLU and ML.

Initially, the class, derived class, strong typing, inlining, and default argument features were added to C via Stroustrup's "C with Classes" to C compiler, Cpre.[7]

In 1983, it was renamed from C with Classes to C++ (++ being the increment operator in C). New features were added including virtual functions, function name and operator overloading, references, constants, type-safe free-store memory allocation (new/delete), improved type checking, and BCPL style single-line comments with two forward slashes (//), as well as the development of a proper compiler for C++, Cfront.

In 1985, the first edition of The C++ Programming Language was released, which became the definitive reference for the language, as there was not yet an official standard.[8] The first commercial implementation of C++ was released in October of the same year.[9]

In 1989 C++ 2.0 was released followed by the updated second edition of The C++ Programming Language in 1991.[10] New features in 2.0 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 feature additions included templates, exceptions, namespaces, new casts, and a boolean type.

In 2011, C++11 was released which added more features and enlarged the standard library further (compared to it in 1998), providing more facilities for C++ programmers to use, with more additions planned for 2014 and 2017.

Etymology

According to Stroustrup: "the name signifies the evolutionary nature of the changes from C".[11] This name is credited to Rick Mascitti (mid-1983)[12] 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. The name 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. A joke goes that the name itself has a bug: due to the use of post-increment, which increments the value of the variable but evaluates to the unincremented value, so C++ is no better than C, and the pre-increment ++C form should have been used instead, so that C++ is better than C.[13]

During C++'s development period, the language had been referred to as "new C", then "C with Classes", before acquiring its final name.

Philosophy

Throughout C++'s life, its development and evolution has been informally governed by a set of rules that its evolution should follow:[14]

  • It must be driven by actual problems and its features should be useful immediately in real world programmes.
  • Every feature should be implementable (with a reasonably obvious way to do so).
  • Programmers should be free to pick their own programming style, and that style should be fully supported by C++.
  • Allowing a useful feature is more important than preventing every possible misuse of C++.
  • It should provide facilities for organising programmes into well defined separate parts, and provide facilities for combining separately developed parts.
  • No implicit violations of the type system (but allow explicit violations that have been explicitly asked for by the programmer).
  • Make user created types have equal support and performance to built in types.
  • Any features that you do not use you do not pay for (e.g. in performance).
  • There should be no language beneath C++ (except assembly language).
  • C++ should work alongside other pre-existing programming languages, rather than being part of its own separate and incompatible programming environment.
  • If what the programmer wants to do is unknown, allow the programmer to specify (provide manual control).

Standardization

Year C++ Standard Informal name
1998 ISO/IEC 14882:1998[15] C++98
2003 ISO/IEC 14882:2003[16] C++03
2007 ISO/IEC TR 19768:2007[17] C++TR1
2011 ISO/IEC 14882:2011[18] C++11
2014 N3690 (working draft C++14)[19] C++14

C++ is standardized by an ISO working group, JTC1/SC22/WG21. So far it has seen three versions of C++ released and is currently working on releasing C++1y.

In 1998, it standardized C++ for the first time as ISO/IEC 14882:1998 (informally known as C++98). In 2003 it then published a new version of the C++ standard, ISO/IEC 14882:2003, which fixed problems which had been identified in C++98.

In 2005, a technical report, called the "Library Technical Report 1" (TR1), was released. While not an official part of the standard, it specified a number of extensions to the standard library, which were then included in the next version of C++ (then C++0x).

The latest major revision of the C++ standard, C++11 (formerly known as C++0x), was approved and released on the 12 August 2011,[20] as 14882:2011.[21]

A small extension to C++11, C++14 (also known as C++1y) featuring mainly bug fixes and small improvements is planned for release in 2014.[22] It holds similar aims as C++03 did to C++98.

After C++1y, a major revision, informally known as C++17, is planned for 2017.[22]

Language

C++ inherits most of C's syntax. The following is Bjarne Stroustrup's version of the Hello world program that uses the C++ Standard Library stream facility to write a message to standard output:[23][24]

# include <iostream>

int main()
{
   std::cout << "Hello, world!\n";
}

Within functions that define a non-void return type, failure to return a value before control reaches the end of the function results in undefined behaviour (compilers typically provide the means to issue a diagnostic in such a case).[25] The sole exception to this rule is the main function, which implicitly returns a value of zero.[26]

Operators and operator overloading

Operators that cannot be overloaded
Operator Symbol
Scope resolution operator ::
Conditional operator ?:
dot operator .
Member selection operator .*
"sizeof" operator sizeof
"typeid" operator typeid

C++ provides more than 35 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 .*) as well as the conditional operator. The rich set of overloadable operators is central to using user created types in C++ as well and as easily as built in types (so that the user using them cannot tell the difference). 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). Overloaded "&&" and "||" operators lose their short-circuit evaluation property.

Memory management

C++ supports four types of memory management:[citation needed]

The fine control over memory management is similar to C, but in contrast with languages that intend to hide such details from the programmer, such as Java, Perl, PHP, and Ruby.

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. 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, because each template instantiation produces a copy of the template code: one for each set of template arguments, however, this is the same amount of code that would be generated, or less, that if the code was written by hand.[27] 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++ that 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 programming (OOP) features to C. It offers classes, which provide the four features commonly present in OOP (and some non-OOP) languages: abstraction, encapsulation, inheritance, and polymorphism. One distinguishing feature of C++ classes compared to classes in other programming languages is support for deterministic destructors, which in turn provide support for the Resource Acquisition is Initialization (RAII) concept.

Encapsulation

Encapsulation is the hiding of information 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 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. Therefore, 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 can hide the details of data implementation, allowing the designer to later fundamentally change the implementation without changing the interface in any way.[28][29]

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 not found in most other languages, allowing a class to be derived from more than one base class; this allows for more elaborate inheritance relationships. For example, a "Flying Cat" class can inherit from both "Cat" and "Flying Mammal". Some other languages, such as C# or Java, 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). An interface as in C# and Java can be defined in C++ as a class containing only pure virtual functions, often known as an abstract base class or "ABC". The member functions of such an abstract base class are normally explicitly defined in the derived class, not inherited implicitly. C++ virtual inheritance exhibits an ambiguity resolution feature called dominance.

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 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 and would result in a compile-time error message.

When declaring a function, a programmer can specify for one or more parameters a default value. 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. Because 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. Contrary to some opinion, template code will not generate a bulk code after compilation with the proper compiler settings.[27]

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 that has no runtime overhead 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[30] allow the most specific implementation of the function to be called, according to the actual run-time type of the object. In C++ implementations, 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) virtual function that 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. A class containing a pure virtual function is called an abstract data type. Objects cannot be created from abstract data types; they 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.

Exception handling

Exception handling is a mechanism in C++ that is used to handle errors in a uniform manner and separately from the main body of a programme's source code.[31]Should an error occur, an exception is thrown (raised), which is then caught by an exception handler. The code that might cause an exception to be thrown goes in a try block (is enclosed in try { and }) and the exceptions are handled in separate catch blocks.

#include<iostream>
#include<vector>

int main()
try {
    std::vector<int> vec{3,4,3,1};
    int i{vec.at(4)};
}
//An exception handler, catches std::out_of_range
catch(std::out_of_range& e) {
    std::cerr<<"Accessing a non-existent element: "<<e.what()<<'\n';
}
catch(std::exception& e) {
    std::cerr<<"Exception thrown: "<<e.what()<<'\n';
}

Unknown exceptions from unknown errors can be caught by the handlers using catch(...) to catch all exceptions. As all the standard library exceptions have std::exception as their base class, catching std::exception will catch all standard library exceptions. As is shown above (e.what()), all exceptions that derive from std::exception have a what() function that provides information about what caused the error - std::out_of_range is a descendent of std::exception.

Standard library

The C++ standard consists of two parts: the core language and the C++ Standard Library; which C++ programmers expect on every major implementation of C++, it includes vectors, lists, maps, algorithms (find, for_each, binary_search, random_shuffle, etc.), sets, queues, stacks, arrays, tuples, input/output facilities (iostream; reading from the console input, reading/writing from files), smart pointers for automatic memory management, regular expression support, multi-threading library, atomics support (allowing a variable to be read or written to be at most one thread at a time without any external synchronisation), time utilities (measurement, getting current time, etc.), a system for converting error reporting that doesn't use C++ exceptions into C++ exceptions, a random number generator and a slightly modified version of the C standard library (to make it comply with the C++ type system).

A large part of the C++ library is based on the STL. This provides 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 105 standard headers, of which 27 are deprecated.

The standard incorporates the STL was originally designed by Alexander Stepanov, who experimented with generic algorithms and containers for many years. When he started with C++, he finally found a language where it was possible to create generic algorithms (e.g., STL sort) that perform even better than, for example, the C standard library qsort, thanks to C++ features like using inlining and compile-time binding instead of function pointers. The standard does not refer to it as "STL", as it is merely a part of the standard library, but the term is still widely used to distinguish it from the rest of the standard library (input/output streams, internationalization, diagnostics, the C library subset, etc.).

Most C++ compilers, and all major ones, provide a standards conforming implementation of the C++ standard library.

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.[32]

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 were, however, attempts to standardize compilers for particular machines or operating systems (for example C++ ABI),[33] though they seem to be largely abandoned now.

With C

C++ is often considered to be a superset of C, but this is not strictly true.[34] 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 or behave differently in C++. For example, C allows implicit conversion from void* to other pointer types, but C++ does not (for type safety reasons). Also, C++ defines many new keywords, such as new and class, which may be used as identifiers (for example, variable names) in a C program.

Some incompatibilities have been removed by the 1999 revision of the C standard (C99), which now supports C++ features such as line comments (//), and declarations mixed with code. On the other hand, C99 introduced a number of new features that C++ did not support, were incompatible or redundant in C++, such as variable-length arrays, native complex-number types (use std::complex class that is, and was also there before C99 existed, in the C++ standard library), designated initializers (use constructors instead), compound literals, the boolean typedef (in C++ it is a fundamental type) and the restrict keyword.[35] Some of the C99-introduced features were included in the subsequent version of the C++ standard, C++11 (out of those which were not redundant).[36][37][38]

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).

See also

References

  1. ^ Stroustrup, Bjarne (1997). "1". The C++ Programming Language (Third ed.). ISBN 0-201-88954-4. OCLC 59193992.
  2. ^ Naugler, David (May 2007). "C# 2.0 for C++ and Java programmer: conference workshop". Journal of Computing Sciences in Colleges. 22 (5). Although C# has been strongly influenced by Java it has also been strongly influenced by C++ and is best viewed as a descendant of both C++ and Java.
  3. ^ Stroustrup, Bjarne (17 February 2014). "C++ Applications". stroustrup.com. Retrieved 5 May 2014.
  4. ^ "ISO/IEC 14882:2011". ISO. Retrieved 3 September 2011.
  5. ^ Stroustrup, Bjarne (7 March 2010). "Bjarne Stroustrup's FAQ: When was C++ invented?". stroustrup.com. Retrieved 16 September 2010.
  6. ^ Stroustrup, Bjarne. "Evolving a language in and for the real world: C++ 1991-2006" (PDF).
  7. ^ Bjarne Stroustrup - HOPL-II paper
  8. ^ Stroustrup, Bjarne. "The C++ Programming Language" (First ed.). Retrieved 16 September 2010.
  9. ^ "Bjarne Stroustrup's FAQ – When was C++ invented?". Retrieved 7 June 2013.
  10. ^ Stroustrup, Bjarne. "The C++ Programming Language" (Second ed.). Retrieved 16 September 2010.
  11. ^ "Bjarne Stroustrup's FAQ – Where did the name "C++" come from?". Retrieved 16 January 2008.
  12. ^ Bjarne Stroustrup - HOPL-II paper
  13. ^ Rishoo Mittal (12/04/2010). "The bug in the name of the C++ language". Tech Zombies. {{cite web}}: Check date values in: |date= (help); External link in |work= (help)
  14. ^ Stroustrup, Bjarne. "Evolving a language in and for the real world: C++ 1991-2006" (PDF).
  15. ^ "ISO/IEC 14882:1998".
  16. ^ "ISO/IEC 14882:2003".
  17. ^ "ISO/IEC TR 19768:2007".
  18. ^ "ISO/IEC 14882:2011".
  19. ^ "N3690". {{cite web}}: Missing or empty |url= (help); Text "https://isocpp.org/files/papers/N3690.pdf" ignored (help)
  20. ^ "We have an international standard: C++0x is unanimously approved". Sutter’s Mill.
  21. ^ "ISO/IEC 14882:2011". ISO. 2 September 2011. Retrieved 3 September 2011.
  22. ^ a b "The Future of C++".
  23. ^ Stroustrup, Bjarne (2000). The C++ Programming Language (Special ed.). Addison-Wesley. p. 46. ISBN 0-201-70073-5.
  24. ^ Stroustrup, Bjarne. "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 than std::endl. Also see Can I write "void main()"? for an explanation of the implicit return 0; in the main function. This implicit return is not available in other functions. {{cite web}}: External link in |postscript= (help); line feed character in |postscript= at position 156 (help)CS1 maint: postscript (link)
  25. ^ ISO/IEC (2003). ISO/IEC 14882:2003(E): Programming Languages – C++ §6.6.3 The return statement [stmt.return] para. 2
  26. ^ ISO/IEC (2003). ISO/IEC 14882:2003(E): Programming Languages – C++ §3.6.1 Main function [basic.start.main] para. 5
  27. ^ a b "Nobody Understands C++: Part 5: Template Code Bloat". http://blog.emptycrate.com/: EmptyCrate Software. Travel. Stuff. 6 May 2008. Retrieved 8 March 2010. On occasion you will read or hear someone talking about C++ templates causing code bloat. I was thinking about it the other day and thought to myself, "self, if the code does exactly the same thing then the compiled code cannot really be any bigger, can it?" [...] And what about compiled code size? Each were compiled with the command g++ <filename>.cpp -O3. Non-template version: 8140 bytes, template version: 8028 bytes! {{cite web}}: External link in |location= (help)
  28. ^ Sutter, Herb; Alexandrescu, Andrei (2004). C++ Coding Standards: 101 Rules, Guidelines, and Best Practices. Addison-Wesley.
  29. ^ Henricson, Mats; Nyquist, Erik (1997). Industrial Strength C++. Prentice Hall. ISBN 0-13-120965-5.
  30. ^ Stroustrup, Bjarne (2000). The C++ Programming Language (Special ed.). Addison-Wesley. p. 310. ISBN 0-201-70073-5. A virtual member function is sometimes called a method.
  31. ^ Stroustrup, Bjarne (2013). The C++ Programming Language. Addison Wesley. pp. 343–388. ISBN 9780321563842.
  32. ^ Sutter, Herb (15 April 2003). "C++ Conformance Roundup". Dr. Dobb's Journal. Retrieved 30 May 2006.
  33. ^ "C++ ABI Summary". 20 March 2001. Retrieved 30 May 2006.
  34. ^ "Bjarne Stroustrup's FAQ – Is C a subset of C++?". Retrieved 5 May 2014.
  35. ^ "C9X – The New C Standard". Retrieved 27 December 2008.
  36. ^ "C++0x Support in GCC". Retrieved 12 October 2010.
  37. ^ "C++0x Core Language Features In VC10: The Table". Retrieved 12 October 2010.
  38. ^ "Clang - C++98, C++11, and C++14 Status". Clang.llvm.org. 12 May 2013. Retrieved 10 June 2013.

Further reading

  • Alexandrescu, Andrei (2001). Modern C++ Design: Generic Programming and Design Patterns Applied. Addison-Wesley. ISBN 0-201-70431-5.
  • Alexandrescu, Andrei; Sutter, Herb (2004). C++ Design and Coding Standards: Rules and Guidelines for Writing Programs. Addison-Wesley. ISBN 0-321-11358-6.
  • Dewhurst, Stephen C. (2005). C++ Common Knowledge: Essential Intermediate Programming. Addison-Wesley. ISBN 0-321-32192-8.
  • Josuttis, Nicolai M. (2012). The C++ Standard Library, A Tutorial and Reference (Second ed.). Addison-Wesley. ISBN 0-321-62321-5.
  • Lippman, Stanley B. (1996). Inside the C++ Object Model. Addison-Wesley. ISBN 0-201-83454-5.
  • Vandevoorde, David; Josuttis, Nicolai M. (2003). C++ Templates: The complete Guide. Addison-Wesley. ISBN 0-201-73484-2.