90: Fix CheckedShl/CheckedShr documentation r=cuviper a=samueltardieu

Fix #57 and more:

- CheckedShl was hinting that None was returned on overflow rather than
  on too large a rhs.
- Ditto for CheckedShr.
- CheckedShr documentation erroneously indicated that a left shift was
  going to be performed instead of a right shift.

Co-authored-by: Samuel Tardieu <sam@rfc1149.net>
This commit is contained in:
bors[bot] 2018-10-09 19:23:03 +00:00
commit 2925f10f40
1 changed files with 8 additions and 6 deletions

View File

@ -195,10 +195,11 @@ checked_impl_unary!(CheckedNeg, checked_neg, isize);
#[cfg(has_i128)] #[cfg(has_i128)]
checked_impl_unary!(CheckedNeg, checked_neg, i128); checked_impl_unary!(CheckedNeg, checked_neg, i128);
/// Performs a left shift that returns `None` on overflow. /// Performs a left shift that returns `None` on shifts larger than
/// the type width.
pub trait CheckedShl: Sized + Shl<u32, Output = Self> { pub trait CheckedShl: Sized + Shl<u32, Output = Self> {
/// Shifts a number to the left, checking for overflow. If overflow happens, /// Checked shift left. Computes `self << rhs`, returning `None`
/// `None` is returned. /// if `rhs` is larger than or equal to the number of bits in `self`.
/// ///
/// ``` /// ```
/// use num_traits::CheckedShl; /// use num_traits::CheckedShl;
@ -240,10 +241,11 @@ checked_shift_impl!(CheckedShl, checked_shl, isize);
#[cfg(has_i128)] #[cfg(has_i128)]
checked_shift_impl!(CheckedShl, checked_shl, i128); checked_shift_impl!(CheckedShl, checked_shl, i128);
/// Performs a right shift that returns `None` on overflow. /// Performs a right shift that returns `None` on shifts larger than
/// the type width.
pub trait CheckedShr: Sized + Shr<u32, Output = Self> { pub trait CheckedShr: Sized + Shr<u32, Output = Self> {
/// Shifts a number to the left, checking for overflow. If overflow happens, /// Checked shift right. Computes `self >> rhs`, returning `None`
/// `None` is returned. /// if `rhs` is larger than or equal to the number of bits in `self`.
/// ///
/// ``` /// ```
/// use num_traits::CheckedShr; /// use num_traits::CheckedShr;