C++字符串格式化

参考链接： C++ vswprintf()

// iniconfig.cpp : 定义控制台应用程序的入口点。

//

#include "stdafx.h"

#include <windows.h>

#include <string>

#include <iostream>

#include <sstream>

using namespace std;

std::string & std_string_format(std::string & _str, const char * _Format, ...) 

{

    std::string tmp;

    va_list marker = NULL;

    va_start(marker, _Format);

    size_t num_of_chars = _vscprintf(_Format, marker);

    if (num_of_chars > tmp.capacity()) {

        tmp.resize(num_of_chars + 1);

    }

    vsprintf_s((char *)tmp.data(), tmp.capacity(), _Format, marker);

    va_end(marker);

    _str = tmp.c_str();

    return _str;

}

std::wstring & std_wstring_format(std::wstring & _str, const wchar_t * _Format, ...)

{

    std::wstring tmp;

    va_list marker = NULL;

    va_start(marker, _Format);

    size_t num_of_chars = _vscwprintf(_Format, marker);

    if (num_of_chars > tmp.capacity()) {

        tmp.resize(num_of_chars + 1);

    }

    vswprintf_s((wchar_t *)tmp.data(), tmp.capacity(), _Format, marker);

    va_end(marker);

    _str = tmp.c_str();

    return _str;

}

int main()

{

    int num = 1234;

    double dnum = 8832.234;

    string strResult;

    string format = "the num is %d,the dnum is %f";

    string ret = std_string_format(strResult, format.c_str(), num, dnum);

    wstring strResult2;

    wstring format2 = L"the num is %d,the dnum is %f";

    wstring ret2 = std_wstring_format(strResult2, format2.c_str(), num, dnum);

    //使用ostringstream格式化字符串

    ostringstream ss;

    ss << "the num is " << num << ",the dnum is " << dnum;

    string strResult3 = ss.str();

    wstringstream ws;

    ws << L"the num is " << num << L",the dnum is " << dnum;

    wstring strResult4 = ws.str();

    return 0;

}