Compilation error for conditional noexcept on MSVC

[davidhunter22]

The line

class modifier<T, impl::void_t<decltype(++std::declval<underlying_type_t<T>&>())>>

in incrementable.hpp and maybe others gives the following error on MSVC up to at least Insiders [12106.202]

1>...\include\strong_type\incrementable.hpp(36,42): error C2065: 'T': undeclared identifier
1>...include\strong_type\incrementable.hpp(36,44): error C2760: syntax error: '>' was unexpected here; expected 'expression'
1>...\include\strong_type\incrementable.hpp(36,18): error C2057: expected constant expression

This is when compiling test_incrementable.cpp

This has been raised as an MSVC bug at https://developercommunity.visualstudio.com/t/Template-parameter-unrecognized-in-noexc/11133545?q=noexecpt
Note the code does build with clang and GCC

Oddly the test case on that issue uses a type called modifier so may have been reduced from code from this project
The issue have been marked as of Aug 17 2026 as Fixed Pending release

I am adding this issue so other people know that this is a known issue.
I will try to remember to come back and update this issue once the compiler fix has been released and the code shown to be compiling.

[LegalizeAdulthood]

compiler explorer link that reproduces this failure on MSVC 19.51:

https://godbolt.org/z/rfKhj9MvY

It succeeds on MSVC 19.50:

https://godbolt.org/z/9x51MPado