I have a float value that needs to be put into a
float val = 2.5;
std::string my_val = val; // error here
Unless you're worried about performance, use string streams:
std::ostringstream ss; ss << myFloat; std::string s(ss.str());
If you're okay with Boost, lexical_cast<> is a convenient alternative:
std::string s = boost::lexical_cast<std::string>(myFloat);
Efficient alternatives are e.g. FastFormat or simply the C-style functions.