Can someone explain me why I am getting syntax error in my func Template?-CodePudding

Can someone explain me what is wrong with my function and how to fix it ?

If the input are integers it should return them as a string

If they are doubles -> set_precision(4) then return them as a string

Also is there a posibility to apply set_precision() to multiple var. in one line ?

Thanks for your replies

#include <iostream>
#include<iomanip>
#include<string>
#include<type_traits>

template<typename T>
 std::string nums_to_string(T a, T b){
    if (std::is_integral<T>){
        return (std::to_string(a)   std::to_string(b));
    }
    std::cout << std::setprecision(4) << std::fixed << a;
    std::cout << std::setprecision(4) << std::fixed << b;
    return (std::to_string(a)   std::to_string(b));
}

int main()
{
    double x{ 22.55 };
    double y{ 50.65 };
    //std::cout << std::setprecision(4) << std::fixed << x;
    /*std::string sX = std::to_string(x);
    std::cout << sX;*/
    std::cout << nums_to_string(x, y);
}`

CodePudding user response：

The documentation says that to check that the type is an intregal, you need to check the 'value' attribute within is_integral. Here the code:

template<typename T>
std::string nums_to_string(T a, T b){
    if (std::is_integral<T>::value){
        return (std::to_string(a)   std::to_string(b));
    }
    std::cout << std::setprecision(4) << std::fixed << a;
    std::cout << std::setprecision(4) << std::fixed << b;
    return (std::to_string(a)   std::to_string(b));
}

As mentioned by someone else, since version 17, is_integral<T>::value has been replaced by is_integral_v<T>

CodePudding user response：

Thank you all , now I got this right. The main problem was with unnecessary std::cout and with wrong form of std::is_integral_v<>