Convert float to std::string in C++

Question

I have a float value that needs to be put into a std::string. How do I convert from float to string?

float val = 2.5; std::string my_val = val; // error here 

Answer 1

As of C++11, the standard C++ library provides the function std::to_string(arg) with various supported types for arg.

Answer 2

Unless you're worried about performance, use string streams:

#include <sstream> //..  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.