NVC++ 20.9 fails to compile code instantiating any std::tuple with GCC 10.2 on C++ 17

Accelerated Computing HPC Compilers nvc, nvc++ and nvfortran
#1

The title pretty much explains it all. The code:

    #include <tuple>

    int main()
    {
        std::tuple<int> t{1};
    }

(Note: the compilation only fails if a value is supplied in the constructor.)
The compilation command is nvc++ test.cpp --c++17

The error is:

"/usr/include/c++/10.2.0/tuple", line 566: error: pack "_UElements" does not
          have the same number of elements as "_Elements"
  	    __and_<is_nothrow_constructible<_Elements, _UElements>...>::value;
  	                                               ^
          detected during instantiation of "bool
                    std::tuple<_Elements...>::__nothrow_constructible<_UElement
                    s...>() [with _Elements=<int>, _UElements=<>]" at line 5 of
                    "test.cpp"

nvc++ -v:
    Export PGI_CURR_CUDA_HOME=/opt/nvidia/hpc_sdk/Linux_x86_64/20.9/cuda/
    Export NVCOMPILER=/opt/nvidia/hpc_sdk/Linux_x86_64/20.9
    Export PGI=/opt/nvidia/hpc_sdk
    nvc++-Warning-No files to process

The OS is x86_64 Arch Linux on the LTS kernel.

#2

Looks to have been a known issue that’s since been fixed in the 20.11 release:

% nvc++ tuple.cpp --c++17 -c  -V20.11
"tuple.cpp", line 5: warning: variable "t" was declared but never referenced
          std::tuple<int> t{1};
                          ^

% nvc++ tuple.cpp --c++17 -c -V20.9
"/home/sw/thirdparty/gcc/gcc-10.2.0/Linux_x86_64/include/c++/10.2.0/tuple",
          line 566: error: pack "_UElements" does not have the same number of
          elements as "_Elements"
            __and_<is_nothrow_constructible<_Elements, _UElements>...>::value;
                                                       ^
          detected during instantiation of "bool
                    std::tuple<_Elements...>::__nothrow_constructible<_UElement
                    s...>() [with _Elements=<int>, _UElements=<>]" at line 5 of
                    "tuple.cpp"

"tuple.cpp", line 5: warning: variable "t" was declared but never referenced
          std::tuple<int> t{1};
                          ^

1 error detected in the compilation of "tuple.cpp".
#3

Thanks for the response. Is version 20.11 available for download yet? The latest version on the download page is listed as 20.9

#4

Not quite, but very soon.

#5

Thanks for your help :)!

#6

Just encountered this issue using the Cuda Toolkit 11.1 on ubuntu 20.04 with GCC-10.

Can confirm upgrading to the Cuda Toolkit 11.2.1 will fix it.

#7

Hi fotofill.holland,

Sorry but I’m clear on your post. The original error was with nvc++ and the GNU 10.2 STL for the host. No CUDA was used. Did you see a similar error with nvcc and that this was fixed in CUDA 11.2?

-Mat