[Bug c++/91377] [8/9/10 Regression] ICE with non-static block scope constexpr, captured in lambda, used as template parameter

[gcc.j.kelling at hzdr dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91377

--- Comment #2 from Jeffrey Kelling <gcc.j.kelling at hzdr dot de> ---
Created attachment 46680
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=46680&action=edit
gcc 7.3.0 preprocessed source

Not sure if it helps, but here is the code preprocessed by gcc 7.3.0.

This compiles with gcc 7.3.0.

gcc 9.1.0 does not like this one:
./thirdParty/alpaka/include/alpaka/vec/Vec.hpp: In instantiation of ‘decltype
(createVecFromIndexedFnArbitrary<TDim, template<long unsigned int <anonymous> >
class TTFnObj>(alpaka::meta::MakeIntegerSequence<typename TDim::value_type,
TDim::value>(),
(forward<TArgs>)(alpaka::vec::createVecFromIndexedFn::args)...))
alpaka::vec::createVecFromIndexedFn(TArgs&& ...) [with TDim =
std::integral_constant<long unsigned int, 3>; TTFnObj =
alpaka::vec::Vec<std::integral_constant<long unsigned int, 3>, unsigned
int>::CreateSingleVal; TArgs = {const unsigned int&}]’:
include/picongpu/main.cpp:70:1:   required from here
./thirdParty/alpaka/include/alpaka/vec/Vec.hpp:99:14: sorry, unimplemented:
mangling implicit_conv_expr