nvcc compile error

[nielskm]

Describe the bug
The const version of Catch::Benchmark::Detail::ObjectStorage::stored_object does not compile with nvcc (invalid type cast). The problem is solved by first casting to const void* and then to void* using const_cast.

I will make a PR ASAP.

[horenmar]

Which nvcc version is that?

[nielskm]

I tested it with CUDA 11.7 (compiler version 11.7.64).

[jbadwaik]

Could you please post the complete error? I'm a little confused at the situation.

nvcc is a device compiler, it offloads the host side compilation to the underlying host compiler (which is most probably gcc). And since Catch does not have any __device__ annotations, the error should actually come from the underlying host GCC compiler. Hence, my curiousity.

[nielskm]

I understand completely, and I agree that the error should come from the host compiler.

I get the following error:
/path/to/catch2/benchmark/catch_constructor.hpp(62): error: invalid type conversion
When compiling the attached example with version 11.7 of the CUDA toolkit.
catch2_nvcc_error.tar.gz

[nielskm]

By the way, I am testing this on Ubuntu 22.04 where the default GCC version is 11.2. I suppose that is the one used by nvcc.

[jbadwaik]

Thank you. Yes. You are correct. I can reproduce this.

T const& stored_object() const {
    return *static_cast<T const*>(static_cast<void const*>(data));
}

I suggest the above fix instead, which does not need any const cast.

[jbadwaik]

As a workaround for now, I will suggest not using catch/catch_all.hpp if possible but instead using fine-grained headers catch_test_macros.hpp and catch_approx.hpp. That will remove the problem of using the benchmark headers.