charls @2.1.0: error: implicit instantiation of undefined template 'std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >'

[ryandesign (Ryan Carsten Schmidt)]

charls does not build:

:info:build /opt/local/var/macports/build/_Users_rschmidt_macports_macports-ports-ryandesign-fork_graphics_charls/charls/work/charls-2.1.0/src/jpegls_error.cpp:19:12: error: implicit instantiation of undefined template 'std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >'
:info:build     string message(int error_value) const override
:info:build            ^
:info:build /Library/Developer/CommandLineTools/usr/include/c++/v1/iosfwd:193:32: note: template is declared here
:info:build     class _LIBCPP_TEMPLATE_VIS basic_string;
:info:build                                ^
:info:build /opt/local/var/macports/build/_Users_rschmidt_macports_macports-ports-ryandesign-fork_graphics_charls/charls/work/charls-2.1.0/src/jpegls_error.cpp:21:16: error: implicit instantiation of undefined template 'std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >'
:info:build         return charls_get_error_message(static_cast<jpegls_errc>(error_value));
:info:build                ^
:info:build /Library/Developer/CommandLineTools/usr/include/c++/v1/iosfwd:193:32: note: template is declared here
:info:build     class _LIBCPP_TEMPLATE_VIS basic_string;
:info:build                                ^
:info:build 2 errors generated.

Here is the upstream bug report:

​https://github.com/team-charls/charls/issues/62

And the fix which you should apply to the port:

​https://github.com/team-charls/charls/commit/5a58c40f0fd38a75cbd3b1ac2d9dc6171a832f47

[ryandesign (Ryan Carsten Schmidt)]

In 3b6a0006b84b62360c8695dbff336e99fde14e71/macports-ports (master):

charls: Include forgotten <string> header

Fixes build with older clangs.

Closes: #60619