字符串转int/float/double

#include<iostream>

#include <sstream>

using namespace std;

template <class Type>

Type stringtoNum(const string& str){

istringstream iss(str);

Type num;

iss>>num;

return num;

}

int main(){

string str("1234.5678");

cout<<stringtoNum<float>(str)<<endl;

return 0;

}