call function that returns int and store into string c++

Question

I am trying to create a string that calls functions and concatenates the return string values. If one of the functions returns an int I get an error. I don't have much experience with overloading operators, but I'm thinking I need to overload the + operator to make this work. Is this correct? Or is there a better way to do this?

string str=getString1()+getString2()+getInt();

You can use getInt().ToString() to convert the integer to a string. — dub stylee, Nov 26 '14 at 20:02
@dubstylee: Did you test that, or are you just making stuff up? — Kerrek SB, Nov 26 '14 at 20:03
@KerrekSB He may have mistaken the question for C#, though IIRC `ToString()` is called implicitly in this situation in C#. — IllusiveBrian, Nov 26 '14 at 20:06
My apologies, I didn't notice C++ before I posted my comment. — dub stylee, Nov 26 '14 at 20:08
Use [`std::to_string()`](http://en.cppreference.com/w/cpp/string/basic_string/to_string) to convert numeric values perhaps? — πάντα ῥεῖ, Nov 26 '14 at 20:10

score 4 · Accepted Answer · edited Nov 26 '14 at 20:03

4

You can use std::to_string.

string str = getString1() + getString2() + std::to_string(getInt());

edited Nov 26 '14 at 20:03

jrok

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answered Nov 26 '14 at 20:03

vincentp

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I'm getting the error more than one instance of overloaded function "to_string" matches the argument list – Jordan Nov 26 '14 at 20:09
@Jordan, If I remember correctly, that was fixed in a later version of VS. – chris Nov 26 '14 at 20:13
I fixed the problem with the type cast _ULonglong. Thank you for the help! – Jordan Nov 26 '14 at 20:15

score 0 · Answer 2 · answered Nov 26 '14 at 20:14

Using std::to_string as suggested by vincent you could also overload the + operator in an easy way:

// string + int
std::string operator+(const std::string &str, const int &i){
    std::string result = str + std::to_string(i);
    return result;
}
// int + string
std::string operator+(const int &i, const std::string &str){
    std::string result = std::to_string(i) + str;
    return result;
}

Then your original code should work as espected.

string str = getString1() + getString2() + getInt();

Example:

td::cout << string("This is a number: ") + 5 << endl;
std::cout << 5 + string(" is a number.") << endl;

Output:

This is a number: 5
5 is a number.

call function that returns int and store into string c++

2 Answers2