Your Environment

• Operating System and version: Kubuntu 18.04
• Compiler: gcc 8.2
• PCL Version: 1.8 latest master

Context

I'm trying to use C++17 in code that is also using PCL.

Expected Behavior

In CMake add_compile_options(-std=c++17 -Wall -Wextra) should add C++17 for all targets in the script.

Current Behavior

C++17 is disabled when linking to PCL (target_link_libraries), preventing from using C++17.

I'm not sure why, but commenting the PCL_LIBRARIES in the CMake script then allows to use C++17. Of course then you can't call any PCL function or it will result in a linking error.

Code to Reproduce

CMakeLists.txt

cmake_minimum_required(VERSION 3.1 FATAL_ERROR)
project(test_pcl)
add_compile_options(-std=c++17 -Wall -Wextra)

find_package(PCL 1.9.1.99 REQUIRED)

include_directories(
  ${PCL_INCLUDE_DIRS}
)

add_executable(
  test_pcl
  test_pcl.cpp
)
target_link_libraries(
  test_pcl
  stdc++fs # filesystem
  ${PCL_LIBRARIES} # Comment and C++17 will be enabled
)

test_pcl.cpp

#include <filesystem>
#include <iostream>
#include <string>

using std::cout;
using std::endl;

int
main(int, char **)
{
  cout << "Test PCL" << endl;
#if __cplusplus >= 201703L
  cout << "C++ >= 201703L" << endl;

  const std::string dir("/");
  for (auto p : std::filesystem::directory_iterator(dir))
    cout << p.path() << endl;
#else
  cout << "C++ < 201703L" << endl;
#endif
  return 0;
}

Program output:

Test PCL
C++ < 201703L

I have tried forcing per target compile options too with no result:

target_compile_options(
  test_pcl
  PUBLIC
  -std=c++17 -Wall -Wextra
)