Platform-independent way to obtain maximum C++ float value

Question

What’s the best, platform-independent way to obtain the maximum value that can be stored in a float in C++?

Answer 1

std::numeric_limits    

Answer 2

std::numeric_limits<float>::max()

Answer 3

std::numeric_limits

// numeric_limits example
#include <iostream>
#include <limits>
using namespace std;

int main () {

  cout << "Minimum value for float: " << numeric_limits<float>::min() << endl;
  cout << "Maximum value for float: " << numeric_limits<float>::max() << endl;
  cout << "Minimum value for double: " << numeric_limits<double>::min() << endl;
  cout << "Maximum value for double: " << numeric_limits<double>::max() << endl;
  return 0;
}

Answer 4

In C++ you can use the std::numeric_limits class to get this sort of information.

If has_infinity is true (which will be true for basically all platforms nowadays), then you can use infinitity to get the value which is greater than or equal to all other values (except NaNs). Similarly, its negation will give a negative infinity, and be less than or equal to all other values (except NaNs again).

If you want finite values, then you can use min/max (which will be less than or equal to/greater than or equal to all other finite values).