[{"id":3672587,"web_url":"http://patchwork.ozlabs.org/comment/3672587/","msgid":"","list_archive_url":null,"date":"2026-04-02T07:48:38","subject":"Re: [PATCH] libstdc++: Use __cpp_lib_map_try_emplace feature test\n macro","submitter":{"id":90409,"url":"http://patchwork.ozlabs.org/api/people/90409/","name":"Tomasz Kaminski","email":"tkaminsk@redhat.com"},"content":"On Thu, Apr 2, 2026 at 9:39 AM Jonathan Wakely wrote:\n\n> Check the relevant macro for insert_or_assign members, instead of just\n> checking the value of __cplusplus.\n>\n> Also use Doxygen grouping to make docs for try_emplace apply to all\n> three overloads.\n>\n> libstdc++-v3/ChangeLog:\n>\n> * include/bits/stl_map.h (map::try_emplace): Move #endif and use\n> Doxygen's @{ to document all three overloads together.\n> (map::insert_or_assign): Use relevant feature test macro.\n> ---\n>\n> Tested x86_64-linux.\n>\nLGTM.\n\n>\n> libstdc++-v3/include/bits/stl_map.h | 11 ++++++-----\n> 1 file changed, 6 insertions(+), 5 deletions(-)\n>\n> diff --git a/libstdc++-v3/include/bits/stl_map.h\n> b/libstdc++-v3/include/bits/stl_map.h\n> index 72a7392dbb77..1e119a95b5cd 100644\n> --- a/libstdc++-v3/include/bits/stl_map.h\n> +++ b/libstdc++-v3/include/bits/stl_map.h\n> @@ -870,6 +870,8 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER\n> * to the first is returned.\n> *\n> * Insertion requires logarithmic time (if the hint is not taken).\n> + *\n> + * @{\n> */\n> template \n> iterator\n> @@ -906,7 +908,6 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER\n> __i = iterator(__true_hint.first);\n> return __i;\n> }\n> -#endif\n>\n> #ifdef __glibcxx_associative_heterogeneous_insertion // C++26\n> template <__heterogeneous_tree_key _Kt, typename ..._Args>\n> @@ -927,6 +928,8 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER\n> return __i;\n> }\n> #endif\n> + /// @}\n> +#endif // __glibcxx_map_try_emplace\n>\n> /**\n> * @brief Attempts to insert a std::pair into the %map.\n> @@ -1074,7 +1077,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER\n> insert(_InputIterator __first, _InputIterator __last)\n> { _M_t._M_insert_range_unique(__first, __last); }\n>\n> -#if __cplusplus > 201402L\n> +#ifdef __glibcxx_map_try_emplace // >= C++17 && HOSTED\n> /**\n> * @brief Attempts to insert or assign a std::pair into the %map.\n> * @param __k Key to use for finding a possibly existing pair in\n> @@ -1150,9 +1153,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER\n> }\n> #endif\n> ///@}\n> -#endif\n>\n> -#if __cplusplus > 201402L\n> ///@{\n> /**\n> * @brief Attempts to insert or assign a std::pair into the %map.\n> @@ -1238,7 +1239,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER\n> }\n> #endif\n> ///@}\n> -#endif\n> +#endif // __glibcxx_map_try_emplace\n>\n> #if __cplusplus >= 201103L\n> // _GLIBCXX_RESOLVE_LIB_DEFECTS\n> --\n> 2.53.0\n>\n>","headers":{"Return-Path":"","X-Original-To":["incoming@patchwork.ozlabs.org","gcc-patches@gcc.gnu.org"],"Delivered-To":["patchwork-incoming@legolas.ozlabs.org","gcc-patches@gcc.gnu.org"],"Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (1024-bit key;\n unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256\n header.s=mimecast20190719 header.b=fpr6d5IM;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=gcc.gnu.org\n (client-ip=2620:52:6:3111::32; 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