clang std::source_location::current() fail

[PaltryProgrammer]

greetings kind regards clang std::current_location::current() results in error as shown MSVC compiles w/o error kindly advise Thank You Kindly

[EugeneZelenko]

Could you please create reproducer on https://godbolt.org ?

[PaltryProgrammer]

i do not know what a "reproducer" is . however w/ clang 15.0.0 as i did not see a 17.0.0 it seems to work as you can see

[fsb4000]

It's expected.

Microsoft STL requires __cpp_consteval to be defined for working source_location https://github.com/microsoft/STL/blob/e7f52446c6f41fddbed31904f594a1f711f85601/stl/inc/source_location#L11

And clang 15 doesn't fully implement cpp_consteval so it doesn't define that macro.

https://godbolt.org/z/soxeEaxnT

Even clang trunk doesn't define that macro: https://godbolt.org/z/K7rMfdW9E

[fsb4000]

Actually it looks like compiler devs just forgot to define that macro: #57094

but maybe some bugs still exist and compiler devs don't want to define the macro.

[llvmbot]

@llvm/issue-subscribers-c-20

[PaltryProgrammer]

if __cpp_consteval is required but not provided why was the compile shown here successful ?

[fsb4000]

if __cpp_consteval is required but not provided why was the compile shown here successful ?

Microsoft STL implementation checks that macro but libc++ and libstdc++ don't check.

(Your example uses libstdc++ , if you add -stdlib=libc++ then your example will use libc++ and as far as I know the compiler explorer can't use Microsoft STL together with clang)

[fsb4000]

if __cpp_consteval is required

std::current_location::current() needs __cpp_consteval 100%.

Look: https://en.cppreference.com/w/cpp/utility/source_location/current

It's consteval

[fsb4000]

Hi @AaronBallman !

Could you give us an update about the __cpp_consteval macro?