cmake中使用boost filesystem

https://my.oschina.net/iamhere/blog/513455

tut1.cpp (来自boost自带的示例代码):

//  filesystem tut1.cpp  ---------------------------------------------------------------//

//  Copyright Beman Dawes 2009

//  Distributed under the Boost Software License, Version 1.0.
//  See http://www.boost.org/LICENSE_1_0.txt

//  Library home page: http://www.boost.org/libs/filesystem

#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;
}

CMakeLists.txt:

cmake_minimum_required(VERSION 3.3)

project(cmaketest CXX)
#project(cmaketest)


set(BOOST_ROOT "/opt/boost")

#set(Boost_USE_STATIC_LIBS ON)
#set(Boost_USE_MULTITHREADED ON)
#set(Boost_USE_STATIC_RUNTIME OFF)


# filesystem依赖system
#
find_package(Boost REQUIRED COMPONENTS
#  regex
filesystem
system
)

if(NOT Boost_FOUND)
  message("未发现Boost")
endif()


aux_source_directory(. srcs)

include_directories(${Boost_INCLUDE_DIRS}
#  /opt/boost/lib
  )


add_executable(hello ${srcs})

target_link_libraries(hello ${Boost_LIBRARIES})

cmake中使用boost

• find_package找不到library，打开boost的debug-on找原因
  • https://blog.csdn.net/lc315yuhuofei/article/details/117999481 (opens new window)
  • set(Boost_DEBUG ON)打开debug，会显示boost在查找过程中的详细信息
  • 里面会有很长的searching for： Searching for LOG_LIBRARY_RELEASE: libboost_log-mgw81-mt-1_72; 这些search的就是cmake指定的编译器对应的lib文件名，需要用相同版本的编译器去编译boost才能获得，否则就会找不到。
• 查找的文件名和编译boost时的编译器不匹配：https://www.cnblogs.com/xueye9/p/14346585.html (opens new window)
  • 当文件名和编译器不匹配时，要么用编译器重新编译boost，要么cmake指定编译boost时用的编译器。
• include添加头文件，
  • https://www.cnblogs.com/hustcpp/p/12922998.html (opens new window)
  • INCLUDE_DIRECTORIES(${Boost_INCLUDE_DIR})，添加了头文件包含目录，才能在代码中正确include对应的头文件。

windows安装boost库

https://blog.csdn.net/s_lisheng/article/details/72871218

• 首先安装好vs2017或者2019
• 下载boost并解压，http://www.boost.org (opens new window)，例如boost_1_64_0
• 在下载解压的boost_1_64_0目录运行cmd，执行bootstrap.bat，生成b2.exe和bjam.exe
• 运行b2.exe stage编译安装boost
• 编译出来的东西是库(lib)，注意用哪个编译器编译出来的库，在用cmake使用的时候，也要用对应的编译器。否则find_package会找不到。

cmake编写示例

project(cmake_test)
CMAKE_MINIMUM_REQUIRED (VERSION 3.0)

# 添加C++17支持
set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED True)

# 设置boost目录
set(BOOST_ROOT D:/software/boost_1_72_0)
find_package(Boost REQUIRED COMPONENTS filesystem log)
# 包含boost头文件和库目录
# message(STATUS "Boost_INCLUDE_DIRS is : ${Boost_INCLUDE_DIRS}")
# message(STATUS "Boost_LIBRARY_DIRS is : ${Boost_LIBRARY_DIRS}")
include_directories(${Boost_INCLUDE_DIRS})
link_directories(${Boost_LIBRARY_DIRS})

# 模块找不到时，可能有用的一些操作
# set(BOOST_LIBRARYDIR D:/software/boost_1_72_0/stage/lib)
# set(Boost_USE_STATIC_LIBS ON)
# set(Boost_DEBUG ON)

# 将当前文件夹中所有的源文件添加到变量DIR_SRCS中
aux_source_directory(. DIR_SRCS)
# 将${DIR_SRCS}所对应的源文件编译成可执行文件cmake_test
add_executable(cmake_test ${DIR_SRCS})