废话

发现一个比较好玩的东西，boost::serialization序列化操作，简单来说感觉像ofstream和ifstream的升级版，Boost.Serialization 库能够将c++项目中的对象转换为一序列的比特（bytes），用来保存和加载还原对象。

在ORBSLAM3保存和加载地图的时候好像就是采用的这种方法，后面需要再深入研究一下。

实战

参考链接：https://www.jianshu.com/p/c2f830cee98c
感觉这个大佬写的很不错，参考了一下他的分享自己写了一个简单的小例子，设计了一个简单的相机信息类CameraInfo。然后对其进行序列化和反序列化操作，也就是对象的写入和加载。

代码文件：

#include <iostream>
#include <fstream>
#include <vector>
#include <string>
#include <boost/archive/binary_iarchive.hpp> //二进制序列化
#include <boost/archive/binary_oarchive.hpp> //二进制序列化
#include <boost/serialization/vector.hpp> //序列化STL容器要导入
#include <boost/serialization/string.hpp>

using namespace std;

class CameraInfo{
public:
    CameraInfo(){};
    CameraInfo(const int _fx, const int _fy, const int _cx, const int _cy, const vector<float> &_vDistortion, string &_CamName);
    ~CameraInfo(){}

    int getFx(){return fx;}
    int getFy(){return fy;}
    int getCx(){return cx;}
    int getCy(){return cy;}
    vector<float> getDistortion(){return mvDistortion;}
    string getCamName(){return CamName;}
private:
    friend class boost::serialization::access;
    template <typename Archive>
    void serialize(Archive &ar, const unsigned int version)
    {
        ar &fx;
        ar &fy;
        ar &cx;
        ar &cy;
        ar &mvDistortion;
        ar &CamName;
    }

    int fx,fy,cx,cy;
    vector<float> mvDistortion;
    string CamName;
};

CameraInfo::CameraInfo(const int _fx, const int _fy, const int _cx, const int _cy, const vector<float> &_vDistortion, string &_CamName)
:fx(_fx),fy(_fy),cx(_cx),cy(_cy),mvDistortion(_vDistortion),CamName(_CamName)
{}

void SaveFileTest()
{
    // 文本写入测试
    vector<float> dist = {0.001, -0.03, 0.0004, 0.004};
    string camName = "realsense";
    CameraInfo cam(222,222,230,230,dist,camName);
    ofstream fout("testfile", ios::binary);
    if(fout.is_open())
    {
        boost::archive::binary_oarchive oa(fout);
        oa << cam;
        fout.close();
    }
    else{
        cout<<"open file failed."<<endl;
        exit(-1);
    }
}

void LoadFileTest()
{
    // 文本读取测试
    CameraInfo cam2;
    ifstream fin("testfile",ios::in|ios::binary);
    fin.seekg(0, ios::end);
    streampos fp = fin.tellg();
    if(fin.is_open() && fp)
    {
        fin.seekg(0);
        boost::archive::binary_iarchive ia(fin);
        ia >> cam2;

        printf("fx = %d, fy=%d, cx=%d, cy=%d\r\n",cam2.getFx(),cam2.getFy(),cam2.getCx(),cam2.getCy());
        vector<float> distortion = cam2.getDistortion();
        printf("Distortion = [%f, %f, %f, %f]\r\n",distortion[0],distortion[1],distortion[2],distortion[3]);
        printf("CamName = %s\r\n",cam2.getCamName().c_str());
    }
    else{
		cout<<"open file failed."<<endl;
        exit(-1);
	}
}

int main(int argc, char** argv)
{
    // 文本写入测试
    SaveFileTest();
    // 文本读取测试
    LoadFileTest();
    return 0;
}

CMakeLists.txt文件

cmake_minimum_required(VERSION 3.10)

project(testSerialize)

set(CMAKE_BUILD_TYPE "Release")

set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS}  -Wall   -O3")
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall   -O3")
set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -march=native")
set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -march=native")

set(EXECUTABLE_OUTPUT_PATH ${PROJECT_SOURCE_DIR})
add_executable(testSerialize testSerialize.cpp)
target_link_libraries(testSerialize -lboost_serialization)

输出结果：