Hi
Maybe I’m doing something wrong but I’ve got a problem with libtorch 1.4.0 (I’m using the pre-built binaries you can find at pytorch.com - Ubuntu 16.04 with gcc-5.4)
The code I’m trying to build is the following one
//Include standard libraries
#include <iostream>

//Define namespace data
//This can be included for example by another header file
namespace data
{
}

//Include torch library
#include <torch/torch.h>

int main(int argc, char* argv[])
{
  std::cout << torch::randn({3, 3}) << std::endl;
  return 0;
}

The CMakeLists.txt is
cmake_minimum_required(VERSION 3.0 FATAL_ERROR)
project(test_variant)

find_package(Torch REQUIRED)

add_executable(test_variant main.cpp)
target_link_libraries(test_variant "${TORCH_LIBRARIES}")
set_property(TARGET test_variant PROPERTY CXX_STANDARD 14)

I’ve added an empty “data” namespace to better explain the problem.
When I build the example I get a lot of errors like
~/test_variant/libtorch/include/c10/util/variant.h:2519:7: error: invalid use of ‘void’
       AUTO_RETURN(v && holds_alternative<I>(*v)


I’ve looked inside the file and it seems that the problem is the statement (line 1165 c10/utils/variant.h)
AUTO_REFREF_RETURN(recursive_union::get_alt(
              data(lib::forward<V>(v)), in_place_index_t<I>{}))

Where “data” is incorrectly detected as the namespace I’ve added before the <torch/torch.h> inclusion.
I think it should refer to the “data” function which can be found  in the same file at line 1743 (I tried to change its name and indeed the error is solved).
Could this be an issue or it’s something I’m doing wrong in my code?
Thank you very much for your help