Return dynamically allocated memory from C++ to C

Question

I have a dll that must be useable from C etc, so I cant use string objects etc as a normal would, but I\'m not sure on how to do this safely..

const char *Ge         


        

Answer 1

If thread-safety is not important,

const char *GetString()
{
    static char *out;
    std::stringstream ss;
    ss << "The random number is: " << rand();
    delete[] out;
    char *out = new char[ss.str().size()];
    strcpy(ss.str().c_str(), out);
    return out;//is out ever deleted?
}

Then the function can take over the responsibility of deallocating the string.

If thread-safety is important,

Then the best method is to pass it in as an argument, as in,

void GetString(char *out, int maxlen);

I observe this is what happens when the old non thread-safe APIs are changed to thread-safe.