From 8f1591763fd50b143af0dc1770741f326a97583a Mon Sep 17 00:00:00 2001 From: Jonathan Wakely Date: Wed, 29 Apr 2020 18:57:34 +0100 Subject: [PATCH] libstdc++: Fix outdated comment about std::string instantiations (PR 94854) PR libstdc++/94854 * include/bits/basic_string.tcc: Update comment about explicit instantiations. --- libstdc++-v3/ChangeLog | 6 ++++++ libstdc++-v3/include/bits/basic_string.tcc | 10 +++++----- 2 files changed, 11 insertions(+), 5 deletions(-) diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index f8cf71e057f..2032e90abeb 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,3 +1,9 @@ +2020-04-29 Jonathan Wakely + + PR libstdc++/94854 + * include/bits/basic_string.tcc: Update comment about explicit + instantiations. + 2020-04-28 Jonathan Wakely PR libstdc++/91480 diff --git a/libstdc++-v3/include/bits/basic_string.tcc b/libstdc++-v3/include/bits/basic_string.tcc index e78bb2c14b3..e370f439390 100644 --- a/libstdc++-v3/include/bits/basic_string.tcc +++ b/libstdc++-v3/include/bits/basic_string.tcc @@ -1609,11 +1609,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION // Inhibit implicit instantiations for required instantiations, // which are defined via explicit instantiations elsewhere. #if _GLIBCXX_EXTERN_TEMPLATE - // The explicit instantiations definitions in src/c++11/string-inst.cc - // are compiled as C++14, so the new C++17 members aren't instantiated. - // Until those definitions are compiled as C++17 suppress the declaration, - // so C++17 code will implicitly instantiate std::string and std::wstring - // as needed. + // The explicit instantiation definitions in src/c++11/string-inst.cc and + // src/c++17/string-inst.cc only instantiate the members required for C++17 + // and earlier standards (so not C++20's starts_with and ends_with). + // Suppress the explicit instantiation declarations for C++20, so C++20 + // code will implicitly instantiate std::string and std::wstring as needed. # if __cplusplus <= 201703L && _GLIBCXX_EXTERN_TEMPLATE > 0 extern template class basic_string; # elif ! _GLIBCXX_USE_CXX11_ABI -- 2.30.2