Question

当我尝试使用boost中的文件系统时，我遇到了链接问题。我复制了教程中的代码：

#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;
}

也许它应该有用，但我有这样的错误：

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

我的CMakeLists.txt文件：

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()

编译此代码可以改进哪些内容？我在OSX上使用CLion编辑器。

Answer 1

在CMakeList.txt中更改此行：

find_package(Boost)

通过

find_package(Boost COMPONENTS system filesystem REQUIRED)

不要忘记与目标建立联系：

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

所以你的CMakeList.txt将是：

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()

使用boost库和clion

1 个答案: