How to use strcat

Problem: I am not able to pass two parameters, concatenate them in dynamically allocated memory, delete the memory and return the concatenated value. It seems like this should be straight forward, but I am running into all types of issues.

Code:

Code:

TestString TestString::concat(const TestString &value) const
{

    //Length
    char *str = new char[(strlen(str) + strlen(value.str) + 1)];

    //strcat
    strcat(str, value.str);

    //delete ??
    //somehow i need to delete before I return the value;
    delete [] str;
    //This most likely to early since I haven't returned anything yet

    //return
    return str;
}

I am not able to pass two parameters, concatenate them in dynamically allocated memory, delete the memory and return the concatenated value.

If you delete the memory, then the string you created in that memory is destroyed.

Thanks to those that looked but I figured it out. I will post my solution in a while.