#include <iostream>
#include <string>
using namespace std;
int main()
{
int a = 55;
double b = 65.123;
string str = "";
//头文件是sstream
std::ostringstream oss;
oss << a << "---" << b;
str = oss.str();
cout << str << endl;
return 0;
}
输出是55—65.123。
如果想实现小数点后只显示一位数字，使用下面方法：
#include <iostream>
#include <sstream>
#include <iomanip>
template <class T>
std::string fmt(T in, int width = 0, int prec = 0) {
std::ostringstream s;
s << std::setw(width) << std::setprecision(prec) << in;
return s.str();
}
int main(){
std::string s = fmt(66.0 / 30.0, 2, 2);
std::cout << s << "\n";
}