为什么 fwrite / fread 不像 56.806201550387598？

Question

我正在尝试将结构保存到文件中，然后在另一个程序中再次读取它。我以前从未遇到过此问题，但至少据我所知，我从未尝试将带有值的双变量写入56.806201550387598文件。并不是说我不知道​​为什么这个数字会产生任何问题，但是每当我尝试将包含该值的结构写入文件时，该字段及其后声明的任何字段都只能从该结构中读出初始化值宣言。

#include <fstream>
#include <iostream>
#include <string> 

using namespace std;

typedef struct statsSet{
    int pathCount = 0;
    double vMinMean = 0;
    int imgsFound = 0;
    int minWidth = INT_MAX;
    int maxWidth = 0; 
}statsSet;

void wrightToFile(statsSet sSet){
    FILE* of = fopen ("imgStats2.dat", "w"); 
    fwrite (&sSet, sizeof(statsSet), 1, of); 
    fclose (of);
}
statsSet readFromFile(){
    statsSet statReadIn;
    FILE *ifl = fopen ("imgStats2.dat" , "r");
    fread(&statReadIn, sizeof(statsSet), 1, ifl);
    fclose (ifl);
    return statReadIn;
}
void pr(statsSet statReadIn){   
    cout << "pathCount: " << statReadIn.pathCount << "\n";
    cout << "vMinMean: " << statReadIn.vMinMean<< "\n";
    cout << "imgsFound: " << statReadIn.imgsFound<< "\n";
    cout << "minWidth: " << statReadIn.minWidth<< "\n";
    cout << "maxWidth: " << statReadIn.maxWidth<< "\n";
    cout << "--------\n";
}

int main( int argc, char** argv ){
    statsSet statTest; 
    statsSet statReadIn;

    statTest.pathCount = 129;
    statTest.imgsFound = 129;
    statTest.minWidth = 488;
    statTest.maxWidth = 501;

    statTest.vMinMean = 56.806201550387591; // OK
    wrightToFile(statTest);
    statReadIn = readFromFile();
    pr(statReadIn);


    statTest.vMinMean = 56.806201550387598;   //breaks
    wrightToFile(statTest);
    statReadIn = readFromFile();
    pr(statReadIn);

    
    statTest.vMinMean = 56.806201550387605; // OK
    wrightToFile(statTest);
    statReadIn = readFromFile();
    pr(statReadIn);
}

输出：

pathCount: 129
vMinMean: 56.8062
imgsFound: 129
minWidth: 488
maxWidth: 501
--------
pathCount: 129
vMinMean: 0
imgsFound: 0
minWidth: 2147483647
maxWidth: 0
--------
pathCount: 129
vMinMean: 56.8062
imgsFound: 129
minWidth: 488
maxWidth: 501
--------

我究竟做错了什么？

我使用的是 Windows 10、Visual Studio Code 和 MinGW-w64。

Answer 1

使用写入二进制模式。文本模式对于二进制数据来说是非常随机的。

FILE* of = fopen ("imgStats2.dat", "wb"); 

和

FILE *ifl = fopen ("imgStats2.dat" , "rb");