1. 代码

tutorial.cpp

#include <iostream>
#include <cmath>
#include <string>
#include "TutorialConfig.h"
using namespace std;

int main(int argc, char* argv[])
{
          
   
    cout << "This is a simple tutorial of camke!" << endl;
    if (argc < 2) {
          
   
        // report version
        cout << argv[0] << " Version " << Tutorial_VERSION_MAJOR << "." << Tutorial_VERSION_MINOR << endl;
        cout << "Usage: " << argv[0] << " number" << endl;
        return 1;
    }

    // convert input to double
    const double inputValue = stod(argv[1]);

    // calculate square root
    const double outputValue = sqrt(inputValue);
    cout << "The square root of " << inputValue << " is " << outputValue << endl;
    return 0;
}

TutorialConfig.h.in通过CMake设置与程序交互的部分：

// the configured options and settings for Tutorial
#define Tutorial_VERSION_MAJOR @Tutorial_VERSION_MAJOR@
#define Tutorial_VERSION_MINOR @Tutorial_VERSION_MINOR@

2. CMakeLists.txt

cmake_minimum_required(VERSION 3.10)
# set the project name and version
project(Tutorial VERSION 1.0)

# specify the C++ standard
set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_STANDARD_REQUIRED true)

# set major version number
set(Tutorial_VERSION_MAJOR 1)
# set minor version nubmer
set(Tutorial_VERSION_MINOR 0)

# copy a file to another location and modify its contents
configure_file(TutorialConfig.h.in TutorialConfig.h)

# Add include directories to the build.
#include_directories("${PROJECT_BINARY_DIR}")

# add the executable
add_executable(Tutorial tutorial.cpp)
# add include directories to a target. 
target_include_directories(Tutorial PUBLIC "${PROJECT_BINARY_DIR}")

3. CMakeLists.txt 解析

3.1 设置版本号的两种方式

1. project()中的一个可以用于指定主版本及次版本，主次版本以.区分
2. 通过set()的方式设置变量的值，依次来设置版本号，此方式更常用

3.1.1 生成用于C++的头文件

configure_file()用于将一个文件输出指定的文件，并将文件中固定格式的内容进行替换为指定的内容。被替换的格式是@VAR@ 或 ${VAR}

3.1.1 指定头文件包含目录

1. include_directories()此函数指定的头文件包含目录是针对这个构建的
2. target_include_directories()指定的头文件包含目录则是针对某个目标的，因此需要在目标之后使用，否则会报出如下错误： CMake Error at CMakeLists.txt:25 (target_include_directories): Cannot specify include directories for target "Tutorial" which is not built by this project.

3.2 设置 C++ 版本

1. CMAKE_CXX_STANDARD表明编译使用到的C++版本
2. CMAKE_CXX_STANDARD_REQUIRED表明CMAKE_CXX_STANDARD是否为必须

4. 参考