diff options
Diffstat (limited to 'library/core/src/num/mod.rs')
-rw-r--r-- | library/core/src/num/mod.rs | 17 |
1 files changed, 5 insertions, 12 deletions
diff --git a/library/core/src/num/mod.rs b/library/core/src/num/mod.rs index c9baa09f4..95dcaf5dd 100644 --- a/library/core/src/num/mod.rs +++ b/library/core/src/num/mod.rs @@ -3,7 +3,6 @@ #![stable(feature = "rust1", since = "1.0.0")] use crate::ascii; -use crate::convert::TryInto; use crate::intrinsics; use crate::mem; use crate::ops::{Add, Mul, Sub}; @@ -278,18 +277,12 @@ macro_rules! widening_impl { macro_rules! conv_rhs_for_unchecked_shift { ($SelfT:ty, $x:expr) => {{ - #[inline] - fn conv(x: u32) -> $SelfT { - // FIXME(const-hack) replace with `.try_into().ok().unwrap_unchecked()`. - // SAFETY: Any legal shift amount must be losslessly representable in the self type. - unsafe { x.try_into().ok().unwrap_unchecked() } - } - #[inline] - const fn const_conv(x: u32) -> $SelfT { - x as _ + // If the `as` cast will truncate, ensure we still tell the backend + // that the pre-truncation value was also small. + if <$SelfT>::BITS < 32 { + intrinsics::assume($x <= (<$SelfT>::MAX as u32)); } - - intrinsics::const_eval_select(($x,), const_conv, conv) + $x as $SelfT }}; } |