diff options
Diffstat (limited to 'library/core/src/num/int_macros.rs')
| -rw-r--r-- | library/core/src/num/int_macros.rs | 43 |
1 files changed, 34 insertions, 9 deletions
diff --git a/library/core/src/num/int_macros.rs b/library/core/src/num/int_macros.rs index 3cbb55af3..fd01f1b26 100644 --- a/library/core/src/num/int_macros.rs +++ b/library/core/src/num/int_macros.rs @@ -471,7 +471,7 @@ macro_rules! int_impl { )] #[must_use = "this returns the result of the operation, \ without modifying the original"] - #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")] + #[rustc_const_unstable(feature = "unchecked_math", issue = "85122")] #[inline(always)] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn unchecked_add(self, rhs: Self) -> Self { @@ -539,7 +539,7 @@ macro_rules! int_impl { )] #[must_use = "this returns the result of the operation, \ without modifying the original"] - #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")] + #[rustc_const_unstable(feature = "unchecked_math", issue = "85122")] #[inline(always)] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn unchecked_sub(self, rhs: Self) -> Self { @@ -607,7 +607,7 @@ macro_rules! int_impl { )] #[must_use = "this returns the result of the operation, \ without modifying the original"] - #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")] + #[rustc_const_unstable(feature = "unchecked_math", issue = "85122")] #[inline(always)] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn unchecked_mul(self, rhs: Self) -> Self { @@ -740,6 +740,31 @@ macro_rules! int_impl { if unlikely!(b) {None} else {Some(a)} } + /// Unchecked negation. Computes `-self`, assuming overflow cannot occur. + /// + /// # Safety + /// + /// This results in undefined behavior when + #[doc = concat!("`self == ", stringify!($SelfT), "::MIN`,")] + /// i.e. when [`checked_neg`] would return `None`. + /// + #[doc = concat!("[`checked_neg`]: ", stringify!($SelfT), "::checked_neg")] + #[unstable( + feature = "unchecked_neg", + reason = "niche optimization path", + issue = "85122", + )] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[rustc_const_unstable(feature = "unchecked_neg", issue = "85122")] + #[inline(always)] + #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces + pub const unsafe fn unchecked_neg(self) -> Self { + // SAFETY: the caller must uphold the safety contract for + // `unchecked_neg`. + unsafe { intrinsics::unchecked_sub(0, self) } + } + /// Checked shift left. Computes `self << rhs`, returning `None` if `rhs` is larger /// than or equal to the number of bits in `self`. /// @@ -772,13 +797,13 @@ macro_rules! int_impl { /// #[doc = concat!("[`checked_shl`]: ", stringify!($SelfT), "::checked_shl")] #[unstable( - feature = "unchecked_math", + feature = "unchecked_shifts", reason = "niche optimization path", issue = "85122", )] #[must_use = "this returns the result of the operation, \ without modifying the original"] - #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")] + #[rustc_const_unstable(feature = "unchecked_shifts", issue = "85122")] #[inline(always)] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn unchecked_shl(self, rhs: u32) -> Self { @@ -820,13 +845,13 @@ macro_rules! int_impl { /// #[doc = concat!("[`checked_shr`]: ", stringify!($SelfT), "::checked_shr")] #[unstable( - feature = "unchecked_math", + feature = "unchecked_shifts", reason = "niche optimization path", issue = "85122", )] #[must_use = "this returns the result of the operation, \ without modifying the original"] - #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")] + #[rustc_const_unstable(feature = "unchecked_shifts", issue = "85122")] #[inline(always)] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn unchecked_shr(self, rhs: u32) -> Self { @@ -1404,7 +1429,7 @@ macro_rules! int_impl { #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] - #[rustc_allow_const_fn_unstable(const_inherent_unchecked_arith)] + #[rustc_allow_const_fn_unstable(unchecked_shifts)] pub const fn wrapping_shl(self, rhs: u32) -> Self { // SAFETY: the masking by the bitsize of the type ensures that we do not shift // out of bounds @@ -1434,7 +1459,7 @@ macro_rules! int_impl { #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] - #[rustc_allow_const_fn_unstable(const_inherent_unchecked_arith)] + #[rustc_allow_const_fn_unstable(unchecked_shifts)] pub const fn wrapping_shr(self, rhs: u32) -> Self { // SAFETY: the masking by the bitsize of the type ensures that we do not shift // out of bounds |