小编non*_*non的帖子

为什么这个程序在运行时给我一个"Debug Assertion Failed"错误信息

#include "stdafx.h"
#include "iostream"
#include "fstream"
#include "string"
using namespace std;

int conv_ch(char b)
{
    int f;
    f=b;
    b=b+0;
    switch(b)
    {
    case 48:
        f=0;
        break;
    case 49:
        f=1;
        break;
    case 50:
        f=2;
        break;
    case 51:
        f=3;
        break;
    case 52:
        f=4;
        break;
    case 53:
        f=5;
        break;
    case 54:
        f=6;
        break;
    case 55:
        f=7;
        break;
    case 56:
        f=8;
        break;
    case 57:
        f=9;
        break;
    default:
        f=0;
    }
    return f;
} 

class Student
{
public:
    string id;
    size_t id_len;
    string first_name; …