Other than being more better, the real reason behind this is subtle: Gecko has an extra test for these as per https://bugzilla.mozilla.org/show_bug.cgi?id=927430, which fails on this condition and suggests to use mozilla::IsNaN, which is equivalent to std::isnan.
Other than being more better, the real reason behind this is subtle: Gecko has an extra test for these as per https://bugzilla.mozilla.org/show_bug.cgi?id=927430, which fails on this condition and suggests to use mozilla::IsNaN, which is equivalent to std::isnan.