C++输入输出

最近看到真么一段代码，就重温了一下C++的输入输出流。代码如下：

#include <iostream>

#include <string>

#include <sstream>



std::string convertToString(double x)

{

    std::ostringstream o;

    if( o << x)

    {

        return o.str();

    }

    

    return "conversion error";

} 



double convertToDouble(const std::string &str)

{

    std::istringstream i(str);

    double x;

    if( i >> x)

    {

        return x;

    }

    

    return 0.0;

    

}



int main()

{

    char b[10];

    std::string a;

    sprintf(b, "%d", 1975);

    a = b;

    std::cout << a << std::endl;

    

    std::string cc = convertToString(1976);

    std::cout << cc << std::endl;

    

    std::string dd = "2016";

    

    int p = convertToDouble(dd) + 2;

    std::cout << p << std::endl;

    

    return 0;

}