Compilation Error with Boost.Geometry and NVCC (CUDA 12.4): '__T0' does not name a type

[MarekZydor]

I'm encountering a compilation error when trying to compile a project using Boost.Geometry with NVCC, part of CUDA 12.4. The project compiles fine with GCC alone, but when NVCC is involved, it throws errors related to type naming in Boost.Geometry's sectionalize.hpp.

This issue is not present when compiling with CUDA versions 12.3 and below

Environment:

• Compiler: GCC 9.5.0, NVCC from CUDA 12.4
• Boost Version: tested on 1.84.0 and 1.79.0
• Build System: Makefile

Error Logs:

[ 33%] Building CUDA object CMakeFiles/testGeometry.dir/main.cu.o
/home/marekz/boost-1.84.0/include/boost/geometry/algorithms/detail/sections/sectionalize.hpp: In function ‘void boost::geometry::detail::sectionalize::enlarge_sections(Sections&, const Strategy&)’:
/home/marekz/boost-1.84.0/include/boost/geometry/algorithms/detail/sections/sectionalize.hpp:739:12: error: ‘__T0’ does not name a type; did you mean ‘__y0’?
  739 |         using gt = decltype(section.bounding_box);
      |            ^~~~
      |            __y0
/home/marekz/boost-1.84.0/include/boost/geometry/algorithms/detail/sections/sectionalize.hpp:740:38: error: ‘__T0’ was not declared in this scope; did you mean ‘__y0’?
  740 |         using ct = typename geometry::coordinate_type<gt>::type;
      |                                      ^~~~
      |                                      __y0
/home/marekz/boost-1.84.0/include/boost/geometry/algorithms/detail/sections/sectionalize.hpp:740:42: error: template argument 1 is invalid
  740 |         using ct = typename geometry::coordinate_type<gt>::type;
      |                                          ^
/home/marekz/boost-1.84.0/include/boost/geometry/algorithms/detail/sections/sectionalize.hpp:741:14: error: ‘ct’ does not name a type; did you mean ‘cs’?
  741 |         static ct const eps = math::scaled_epsilon<ct>(1000);
      |              ^~
      |              cs
/home/marekz/boost-1.84.0/include/boost/geometry/algorithms/detail/sections/sectionalize.hpp:742:43: error: ‘eps’ was not declared in this scope
  742 |         expand_by_epsilon(section.bounding_box, eps);
      |                                           ^~~
make[3]: *** [CMakeFiles/testGeometry.dir/build.make:76: CMakeFiles/testGeometry.dir/main.cu.o] Error 1
make[2]: *** [CMakeFiles/Makefile2:83: CMakeFiles/testGeometry.dir/all] Error 2
make[1]: *** [CMakeFiles/Makefile2:90: CMakeFiles/testGeometry.dir/rule] Error 2
make: *** [Makefile:124: testGeometry] Error 2

To produce the problem I created a test program:
CMakeLists.txt:

cmake_minimum_required(VERSION 3.22)
project(testGeometry CXX)

set(CMAKE_C_COMPILER "/usr/bin/gcc-9")
set(CMAKE_CXX_COMPILER "/usr/bin/g++-9")
set(CMAKE_CUDA_HOST_COMPILER "/usr/bin/g++-9")

set(CMAKE_CXX_STANDARD 17)

enable_language(CUDA)

include(FindCUDAToolkit)

set(CMAKE_CUDA_FLAGS "${CMAKE_CUDA_FLAGS} --std c++17")
set(CMAKE_CUDA_FLAGS "${CMAKE_CUDA_FLAGS} --maxrregcount 32")
set(CMAKE_CUDA_FLAGS "${CMAKE_CUDA_FLAGS} --expt-relaxed-constexpr")
set(CMAKE_CUDA_SEPARABLE_COMPILATION ON)

set(CMAKE_PREFIX_PATH "${CMAKE_PREFIX_PATH};/home/marekz/boost-1.84.0/lib/cmake")
find_package(Boost REQUIRED)

add_executable(${PROJECT_NAME} main.cu)

target_link_libraries(${PROJECT_NAME}
        PUBLIC
        CUDA::cudart
        Boost::headers
        PRIVATE
        CUDA::curand
        CUDA::cusolver
)

main.cu

#include <boost/geometry.hpp>
#include <boost/geometry/geometries/point_xy.hpp>
#include <boost/geometry/geometries/polygon.hpp>
#include <iostream>

int main()
{
    // Define the point type
    using point_t = boost::geometry::model::d2::point_xy<double>;

    // Define the polygon type
    using polygon_t = boost::geometry::model::polygon<point_t>;

    // Create a point
    point_t point(5.0, 5.0);

    // Create a polygon
    polygon_t poly;
    boost::geometry::append(poly.outer(), point_t(0.0, 0.0));
    boost::geometry::append(poly.outer(), point_t(0.0, 10.0));
    boost::geometry::append(poly.outer(), point_t(10.0, 10.0));
    boost::geometry::append(poly.outer(), point_t(10.0, 0.0));
    boost::geometry::append(poly.outer(), point_t(0.0, 0.0));

    // Calculate the distance
    double dist = boost::geometry::distance(point, poly);

    std::cout << "Distance between the point and the polygon is: " << dist << std::endl;

    return 0;
}

[barendgehrels]

I cannot explain the compiler error, but apparently the first decltype fails. In this case it can be replaced by using typename so that should fix it. Please report if it does not fix it.

[MarekZydor]

Yes, that fixed the issue. It can be closed.

[barendgehrels]

Cool, thanks for confirming it.