Best way to create a string containing multiple copies of another string

Question

I want to create a function that will take a string and an integer as parameters and return a string that contains the string parameter repeated the given number of times.

For example:

std::string MakeDuplicate( const std::string& str, int x )
{
    ...
}

Calling MakeDuplicate( "abc", 3 ); would return "abcabcabc".

I know I can do this just by looping x number of times but I'm sure there must be a better way.

Answer 1

I don't see a problem with looping, just make sure you do a reserve first:

std::string MakeDuplicate( const std::string& str, int x )
{
    std::string newstr;
    newstr.reserve(str.length()*x); // prevents multiple reallocations

    // loop...

    return newstr;
}

Answer 2

At some point it will have to be a loop. You may be able to hide the looping in some fancy language idiom, but ultimately you're going to have to loop.