Handle to_f64() with raw division by zero #83
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You're not really supposed to have a zero denominator, but it's possible with `Ratio::new_raw`, and we can treat that more carefully when converting to floats. If the numerator is also zero, return `None` rather than using NaN. Otherwise, return `Some(±infinity)` matching the sign of the numerator.
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The implementation of `<f64 as ToPrimitive>::to_f32` was written at a time when float-to-float overflow was though to be undefined behavior, per rust-lang/rust#15536, but this was later determined to be fine. Casting a large `f64` to `f32` just results in an infinity with the matching sign. The sign gives more information than if `to_f32` just returns `None`, so now we let these infinities through as a result. See also rust-num/num-bigint#163 and rust-num/num-rational#83.
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185: Trust the "i128" feature r=cuviper a=cuviper If the "i128" feature is explicity requested, don't bother probing for it. It will still cause a build error if that was set improperly. 186: Allow large f64-to-f32 to saturate to infinity r=cuviper a=cuviper The implementation of `<f64 as ToPrimitive>::to_f32` was written at a time when float-to-float overflow was though to be undefined behavior, per rust-lang/rust#15536, but this was later determined to be fine. Casting a large `f64` to `f32` just results in an infinity with the matching sign. The sign gives more information than if `to_f32` just returns `None`, so now we let these infinities through as a result. See also rust-num/num-bigint#163 and rust-num/num-rational#83. 190: Normalize the comment style r=cuviper a=cuviper Co-authored-by: Josh Stone <cuviper@gmail.com>
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You're not really supposed to have a zero denominator, but it's possible
with
Ratio::new_raw, and we can treat that more carefully whenconverting to floats. If the numerator is also zero, return
Nonerather than using NaN. Otherwise, return
Some(±infinity)matching thesign of the numerator.