Cannot build OpenStudio SDK on up-to-date mac with Apple Clang 17.0

[jmarrec]

Issue overview

A recent update to mac brought me apple-clang 17. And now I cannot build OpenStudio SDK.

@anchapin please do make sure you do NOT update the mac CIs yet.

Current Behavior

I'm getting some compiler warnings turned as error that I can work around:

• -Wmissing-template-arg-list-after-template-kw in nano_signal_slot
• -Wenum-constexpr-conversion needs to be defined globally for boost

But then I hit an infamous issue: std::char_traits REMOVAL.

/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/c++/v1/string:1062:17: error: implicit instantiation of undefined template 'std::char_traits<unsigned char>'
 1062 |     __init(__s, traits_type::length(__s));
      |                 ^
/Users/julien/.conan2/p/b/cppre2b2f2b4fe8a41/p/include/cpprest/streams.h:83:16: note: in instantiation of function template specialization 'std::basic_string<unsigned char>::basic_string<0>' requested here
   83 |         return reinterpret_cast<const uint8_t*>(ss.str().c_str());
      |                ^
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/c++/v1/__fwd/string.h:23:29: note: template is declared here
   23 | struct _LIBCPP_TEMPLATE_VIS char_traits;
      |                             ^
2 errors generated.
ninja: build stopped: subcommand failed.

Expected Behavior

Steps to Reproduce

Possible Solution

Details

Environment

Some additional details about your environment for this issue (if relevant):

• Platform (Operating system, version):
• Version of OpenStudio (if using an intermediate build, include SHA):

Context

[jmarrec]

• Fails to build on recent libc++ (20 tested) microsoft/cpprestsdk#1812