“Rustarmanriaziconceptnan” Ответ

Rustarmanriaziconceptnan

Floating-point types include “not a number” values (represented in Rust syntax as NAN values) to handle these cases.
NAN values poison other numbers. 
Almost all operations interacting with NAN return NAN. 
Another thing to be mindful of is that, by definition, NAN values are never equal. 
To program defensively, make use of the is_nan() and is_finite() methods. Inducing a crash, rather than silently proceeding with a mathematical error, allows you to debug close to what has caused the problem. The following illustrates using the is_finite()