title: C++ Standards Support in GCC - GNU Project.md
toc: true
date: 2021-12-22 09:25:00
实时链接 https://gcc.gnu.org/projects/cxx-status.html
下述内容采集于 January 12, 2021
GCC supports different dialects of C++, corresponding to the multiple published ISO standards. Which standard it implements can be selected using the -std= command-line option.
For information about the status of C++ defect reports, please see this page.
For information about the status of the library implementation, please see the Implementation Status section of the Libstdc++ manual.
GCC has experimental support for the latest revision of the C++ standard, which was published in 2020.
C++20 features are available since GCC 8. To enable C++20 support, add the command-line parameter -std=c++20 (use -std=c++2a in GCC 9 and earlier) to your g++ command line. Or, to enable GNU extensions in addition to C++20 features, add -std=gnu++20.
Important: Because the ISO C++20 standard is very recent, GCC’s support is experimental.
The following table lists new language features that have been accepted into the C++20 working draft. The “Proposal” column provides a link to the ISO C++ committee proposal that describes the feature, while the “Available in GCC?” column indicates the first version of GCC that contains an implementation of this feature (if it has been implemented).
GCC has almost full support for the previous revision of the C++ standard, which was published in 2017. Some library features are missing or incomplete, as described in the library documentation.
C++17 features are available since GCC 5. This mode is the default in GCC 11; it can be explicitly selected with the -std=c++17 command-line flag, or -std=gnu++17 to enable GNU extensions as well.
The following table lists new language features that have been accepted into the C++17 working draft. The “Proposal” column provides a link to the ISO C++ committee proposal that describes the feature, while the “Available in GCC?” column indicates the first version of GCC that contains an implementation of this feature (if it has been implemented).
GCC also implements experimental support for some language Technical Specifications published by the C++ committee.
Important: Because these Technical Specifications are still evolving toward future inclusion in a C++ standard, GCC’s support is experimental. No attempt will be made to maintain backward compatibility with implementations of features that do not reflect the final standard.
GCC has full support for the of the 2014 C++ standard.
This mode is the default in GCC 6.1 up until GCC 10 (including); it can be explicitly selected with the -std=c++14 command-line flag, or -std=gnu++14 to enable GNU extensions as well.
The following table lists new language features that are part of the C++14 standard. The “Proposal” column provides a link to the ISO C++ committee proposal that describes the feature, while the “Available in GCC?” column indicates the first version of GCC that contains an implementation of this feature.
[Untitled](C++ Standards Support in GCC - GNU Project/Untitled Database1.csv)
This feature was briefly part of the C++14 working paper, but was not part of the published standard; as a result, it has been removed from the compiler.
GCC 4.8.1 was the first feature-complete implementation of the 2011 C++ standard, previously known as C++0x.
This mode can be selected with the -std=c++11 command-line flag, or -std=gnu++11 to enable GNU extensions as well.
For information about C++11 support in a specific version of GCC, please see:
[Untitled](C++ Standards Support in GCC - GNU Project/Untitled Database2.csv)
GCC has full support for the 1998 C++ standard as modified by the 2003 technical corrigendum and some later defect reports, excluding the export feature which was later removed from the language.
This mode is the default in GCC versions prior to 6.1; it can be explicitly selected with the -std=c++98 command-line flag, or -std=gnu++98 to enable GNU extensions as well.