Linking with error using boost library and clion

Question

I have a linking problem, when I am trying to use filesystem from boost. I copied code from tutorial:

#include <iostream>
#include <boost/filesystem.hpp>
using namespace boost::filesystem;

int main(int argc, char* argv[])
{
    if (argc < 2)
    {
        std::cout << "Usage: tut1 path\n";
        return 1;
    }
    std::cout << argv[1] << " " << file_size(argv[1]) << '\n';
    return 0;
}

Perhaps it should work, but I have such an error:

Scanning dependencies of target untitled
[ 50%] Building CXX object CMakeFiles/untitled.dir/main.cpp.o
[100%] Linking CXX executable untitled
Undefined symbols for architecture x86_64:
  "boost::filesystem::detail::file_size(boost::filesystem::path const&, boost::system::error_code*)", referenced from:
      boost::filesystem::file_size(boost::filesystem::path const&) in main.cpp.o
  "boost::system::system_category()", referenced from:
      ___cxx_global_var_init.2 in main.cpp.o
  "boost::system::generic_category()", referenced from:
      ___cxx_global_var_init in main.cpp.o
      ___cxx_global_var_init.1 in main.cpp.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[3]: *** [untitled] Error 1
make[2]: *** [CMakeFiles/untitled.dir/all] Error 2
make[1]: *** [CMakeFiles/untitled.dir/rule] Error 2
make: *** [untitled] Error 2

My CMakeLists.txt file:

cmake_minimum_required(VERSION 3.7)
project(untitled)

set(CMAKE_CXX_STANDARD 11)

set(SOURCE_FILES main.cpp)
add_executable(untitled ${SOURCE_FILES})

find_package(Boost)
IF (Boost_FOUND)
    include_directories(${Boost_INCLUDE_DIR})
endif()

What can I improve to compile this code? I use CLion editor on OSX.

Answer 1

Change this line in your CMakeList.txt:

find_package(Boost)

by

find_package(Boost COMPONENTS system filesystem REQUIRED)

And don't forget to link with your target:

target_link_libraries(untitled 
  ${Boost_FILESYSTEM_LIBRARY}
  ${Boost_SYSTEM_LIBRARY}
)

So your CMakeList.txt will be:

cmake_minimum_required(VERSION 3.7)
project(untitled)

set(CMAKE_CXX_STANDARD 11)

set(SOURCE_FILES main.cpp)
add_executable(untitled ${SOURCE_FILES})

find_package(Boost COMPONENTS system filesystem REQUIRED)
IF (Boost_FOUND)
    include_directories(${Boost_INCLUDE_DIR})
    target_link_libraries(untitled 
        ${Boost_FILESYSTEM_LIBRARY}
        ${Boost_SYSTEM_LIBRARY}
        )
endif()