diff options
Diffstat (limited to 'library/std/src/f16.rs')
| -rw-r--r-- | library/std/src/f16.rs | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/library/std/src/f16.rs b/library/std/src/f16.rs index 033a3d45009..b2cd5fae9d0 100644 --- a/library/std/src/f16.rs +++ b/library/std/src/f16.rs @@ -249,9 +249,14 @@ impl f16 { /// /// Equal to `self` if the sign of `self` and `sign` are the same, otherwise equal to `-self`. /// If `self` is a NaN, then a NaN with the same payload as `self` and the sign bit of `sign` is - /// returned. Note, however, that conserving the sign bit on NaN across arithmetical operations - /// is not generally guaranteed. See [specification of NaN bit - /// patterns](primitive@f32#nan-bit-patterns) for more info. + /// returned. + /// + /// If `sign` is a NaN, then this operation will still carry over its sign into the result. Note + /// that IEEE 754 doesn't assign any meaning to the sign bit in case of a NaN, and as Rust + /// doesn't guarantee that the bit pattern of NaNs are conserved over arithmetic operations, the + /// result of `copysign` with `sign` being a NaN might produce an unexpected or non-portable + /// result. See the [specification of NaN bit patterns](primitive@f32#nan-bit-patterns) for more + /// info. /// /// # Examples /// |