C++通过ostringstream实现任意类型转string

#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;
}

#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";
}