C++ Language

GCC supports the original ISO C++ standard published in 1998, and the 2011, 2014, 2017 and mostly 2020 revisions.

The original ISO C++ standard was published as the ISO standard (ISO/IEC 14882:1998) and amended by a Technical Corrigenda published in 2003 (ISO/IEC 14882:2003). These standards are referred to as C++98 and C++03, respectively. GCC implements the majority of C++98 (export is a notable exception) and most of the changes in C++03. To select this standard in GCC, use one of the options -ansi, -std=c++98, or -std=c++03 ; to obtain all the diagnostics required by the standard, you should also specify -pedantic (or -pedantic-errors if you want them to be errors rather than warnings).

A revised ISO C++ standard was published in 2011 as ISO/IEC 14882:2011, and is referred to as C++11; before its publication it was commonly referred to as C++0x. C++11 contains several changes to the C++ language, all of which have been implemented in GCC. For details see https://gcc.gnu.org/projects/cxx-status.html#cxx11. To select this standard in GCC, use the option -std=c++11.

Another revised ISO C++ standard was published in 2014 as ISO/IEC 14882:2014, and is referred to as C++14; before its publication it was sometimes referred to as C++1y. C++14 contains several further changes to the C++ language, all of which have been implemented in GCC. For details see https://gcc.gnu.org/projects/cxx-status.html#cxx14. To select this standard in GCC, use the option -std=c++14.

The C++ language was further revised in 2017 and ISO/IEC 14882:2017 was published. This is referred to as C++17, and before publication was often referred to as C++1z. GCC supports all the changes in that specification. For further details see https://gcc.gnu.org/projects/cxx-status.html#cxx17. Use the option -std=c++17 to select this variant of C++.

Another revised ISO C++ standard was published in 2020 as ISO/IEC 14882:2020, and is referred to as C++20; before its publication it was sometimes referred to as C++2a. GCC supports most of the changes in the new specification. For further details see https://gcc.gnu.org/projects/cxx-status.html#cxx20. To select this standard in GCC, use the option -std=c++20.

More information about the C++ standards is available on the ISO C++ committee’s web site at http://www.open-std.org/jtc1/sc22/wg21/.

To obtain all the diagnostics required by any of the standard versions described above you should specify -pedantic or -pedantic-errors, otherwise GCC will allow some non-ISO C++ features as extensions. See Options to Request or Suppress Warnings.

By default, GCC also provides some additional extensions to the C++ language that on rare occasions conflict with the C++ standard. See Options Controlling C++ Dialect. Use of the -std options listed above disables these extensions where they they conflict with the C++ standard version selected. You may also select an extended version of the C++ language explicitly with -std=gnu++98 (for C++98 with GNU extensions), or -std=gnu++11 (for C++11 with GNU extensions), or -std=gnu++14 (for C++14 with GNU extensions), or -std=gnu++17 (for C++17 with GNU extensions), or -std=gnu++20 (for C++20 with GNU extensions).

The default, if no C++ language dialect options are given, is -std=gnu++17.