Including only any_range.hpp of Boost 1.89 fails in const_reference_type_generator

[brandl-muc]

Including <boost/range/any_range.hpp> leads to the following compiler error(s) when compiling with MSVC 17.14.9:

1>------ Build started: Project: BoostAnyRange, Configuration: Debug x64 ------
1>BoostAnyRange.cpp
1>D:\Projects\SO\EOSLibsInventoy\out\build\v143-x64-debug-ninja-vcpkg\vcpkg_installed\x64-windows-v143\include\boost\range\detail\any_iterator_interface.hpp(30,26): error C2146: syntax error: missing '>' before identifier 'add_const'
1>(compiling source file 'BoostAnyRange.cpp')
1>    D:\Projects\SO\EOSLibsInventoy\out\build\v143-x64-debug-ninja-vcpkg\vcpkg_installed\x64-windows-v143\include\boost\range\detail\any_iterator_interface.hpp(30,26):
1>    the template instantiation context (the oldest one first) is
1>        D:\Projects\SO\EOSLibsInventoy\out\build\v143-x64-debug-ninja-vcpkg\vcpkg_installed\x64-windows-v143\include\boost\range\detail\any_iterator_interface.hpp(26,16):
1>        while compiling class template 'boost::range_detail::const_reference_type_generator'
1>D:\Projects\SO\EOSLibsInventoy\out\build\v143-x64-debug-ninja-vcpkg\vcpkg_installed\x64-windows-v143\include\boost\range\detail\any_iterator_interface.hpp(30,35): error C2947: expecting '>' to terminate template-argument-list, found '<'
1>(compiling source file 'BoostAnyRange.cpp')
1>D:\Projects\SO\EOSLibsInventoy\out\build\v143-x64-debug-ninja-vcpkg\vcpkg_installed\x64-windows-v143\include\boost\range\detail\any_iterator_interface.hpp(28,30): error C2062: type '<error type>' unexpected
1>(compiling source file 'BoostAnyRange.cpp')
1>D:\Projects\SO\EOSLibsInventoy\out\build\v143-x64-debug-ninja-vcpkg\vcpkg_installed\x64-windows-v143\include\boost\range\detail\any_iterator_interface.hpp(32,20): error C2039: 'type': is not a member of '`global namespace''
1>(compiling source file 'BoostAnyRange.cpp')
1>D:\Projects\SO\EOSLibsInventoy\out\build\v143-x64-debug-ninja-vcpkg\vcpkg_installed\x64-windows-v143\include\boost\range\detail\any_iterator_interface.hpp(34,16): error C2039: 'type': is not a member of '`global namespace''
1>(compiling source file 'BoostAnyRange.cpp')
1>D:\Projects\SO\EOSLibsInventoy\out\build\v143-x64-debug-ninja-vcpkg\vcpkg_installed\x64-windows-v143\include\boost\range\detail\any_iterator_interface.hpp(34,25): error C2238: unexpected token(s) preceding ';'
1>(compiling source file 'BoostAnyRange.cpp')
1>Done building project "BoostAnyRange.vcxproj" -- FAILED.

The error happens independent of the /std:c++ language standard used. This works with Boost 1.67.0 without any other changes.

A MRE would be this:

#include <boost/range/any_range.hpp>

int main()
{}

[brandl-muc]

Copilot suggests the following:

The error C2146: syntax error: missing '>' before identifier 'add_const' is caused because the add_const type trait is not found in the current scope. In Boost, it is defined in the header <boost/type_traits/add_const.hpp>.

• Make sure to include this header at the top of your file.
• Also, use the fully qualified name boost::add_const if not already in the boost namespace, to avoid ambiguity.
• No other code needs to be changed; just ensure the include is present and the correct namespace is used.

And indeed, adding this include before any_range.hpp as in the following fixes the issue:

#include <boost/type_traits/add_const.hpp>
#include <boost/range/any_range.hpp>

int main()
{}

[brandl-muc]

A similar error happens with gcc (trunk) and clang (trunk).
Applying the suggested fix helps with gcc and clang.