reinterpret_cast And print hex

#include <iostream>
#include <iomanip>
#include <cstdio>
#include <fstream>
using namespace std;

// CPP program to demonstrate working of
// reinterpret_cast
void TestReinterpret_cast()
{
    int* p = new int(65);
    char* ch = reinterpret_cast<char*>(p);
    cout << *p << endl;
    cout << *ch << endl;
    cout << p << endl;
    cout << ch << endl;
}

//Hex
void ToolPrintHex()
{ 
    ofstream file;
    file.open("data_.log",std::ios_base::trunc);       

    char b[] = "ABCEDFG";                                        //b始终指向他所代表的数组在内存中的位置，始终可写！
    const char* a  = b;                                          //a指向的是一个字符串常量，即指向的内存区域只读；
    int len = sizeof(b) / sizeof(char) - 1;                      //=8,最后有一个'\0'
    for (int i = 0; i < len; i++)
    {
        cout <<   i <<":"           << a[i]    <<" ";           //(a+i):BCDEFG,CDEFG...
        cout << hex << setfill(' ') << setw(2) << (unsigned int)(unsigned char)(a[i])  << " ";
        cout << hex << setfill(' ') << setw(2) << (int)b[i]<<endl<<flush;
        file << hex << setfill(' ') << setw(2) << (unsigned int)(unsigned char)(a[i]) << " ";
    }
}