https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110894
--- Comment #1 from Johel Ernesto Guerrero Peña <johelegp at gmail dot com> --- If instead I use `std::string_view` in `-O3` (`-O0` works), it also diagnoses (<https://cpp2.godbolt.org/z/h7zooM35G>): ``` In file included from /app/module.cpp:2, of module hello, imported at /app/main.cpp:2: In member function 'constexpr const std::basic_string_view<_CharT, _Traits>::value_type* std::basic_string_view<_CharT, _Traits>::data() const [with _CharT = char; _Traits = std::char_traits<char>]', inlined from 'std::basic_ostream<_CharT, _Traits>& std::operator<<(basic_ostream<_CharT, _Traits>&, basic_string_view<_CharT, _Traits>) [with _CharT = char; _Traits = char_traits<char>]' at /opt/compiler-explorer/gcc-trunk-20230801/include/c++/14.0.0/string_view:762:30, inlined from 'int main()' at /app/main.cpp:3:46: /opt/compiler-explorer/gcc-trunk-20230801/include/c++/14.0.0/string_view:292:22: warning: 'this' is used uninitialized [-Wuninitialized] 292 | { return this->_M_str; } | ^~~~~~ In file included from /opt/compiler-explorer/gcc-trunk-20230801/include/c++/14.0.0/bits/basic_string.h:47, from /opt/compiler-explorer/gcc-trunk-20230801/include/c++/14.0.0/string:54, from /opt/compiler-explorer/gcc-trunk-20230801/include/c++/14.0.0/bits/locale_classes.h:40, from /opt/compiler-explorer/gcc-trunk-20230801/include/c++/14.0.0/bits/ios_base.h:41, from /opt/compiler-explorer/gcc-trunk-20230801/include/c++/14.0.0/ios:44, from /opt/compiler-explorer/gcc-trunk-20230801/include/c++/14.0.0/ostream:40, from /opt/compiler-explorer/gcc-trunk-20230801/include/c++/14.0.0/iostream:41, from /app/main.cpp:1: /opt/compiler-explorer/gcc-trunk-20230801/include/c++/14.0.0/string_view: In function 'int main()': /opt/compiler-explorer/gcc-trunk-20230801/include/c++/14.0.0/string_view:760:5: note: 'this' was declared here 760 | operator<<(basic_ostream<_CharT, _Traits>& __os, | ^~~~~~~~ ```
