Is `std::atof` guaranteed to produce identical output when given identical string input?

  atof, c++, double, unordered-map

I’m reading double values from file as strings and parsing them with std::atof. Afterwards, I’m using the values as keys in a unordered map. It’s seems to be working correctly, but is it guaranteed to work in 100% of the cases?

I’m asking the question because it’s extremely hard to produce identical double value if you do any arithmetic operations with it.

Is std::atof guaranteed to produce exactly the same double value if given the same string value multiple times?

Source: Windows Questions C++