Tracking Issue for inherent unchecked integer methods #85122
Description
This is a tracking issue for the unchecked_* methods on integers.
unchecked_math (stable as of #122520)
impl uN {
pub const unsafe fn unchecked_add(self, rhs: uN) -> uN;
pub const unsafe fn unchecked_sub(self, rhs: uN) -> uN;
pub const unsafe fn unchecked_mul(self, rhs: uN) -> uN;
}
impl iN {
pub const unsafe fn unchecked_add(self, rhs: iN) -> iN;
pub const unsafe fn unchecked_sub(self, rhs: iN) -> iN;
pub const unsafe fn unchecked_mul(self, rhs: iN) -> iN;
}Steps / History
- Rework the std::iter::Step trait #69659 added
unchecked_{add,sub,mul} - Make unchecked_{add,sub,mul} inherent methods unstably const #85096
- Clean up unchecked_math, separate out unchecked_shifts #115626
- Stabilize
unchecked_{add,sub,mul}#122520 - Add assert_unsafe_precondition to unchecked_{add,sub,neg,mul,shl,shr} methods #121571
unchecked_neg
impl iN {
pub const unsafe fn unchecked_neg(self) -> iN;
}Steps / History
- Clean up unchecked_math, separate out unchecked_shifts #115626 added
unchecked_neg - Add assert_unsafe_precondition to unchecked_{add,sub,neg,mul,shl,shr} methods #121571
unchecked_shifts
impl uN {
pub const unsafe fn unchecked_shl(self, rhs: u32) -> uN;
pub const unsafe fn unchecked_shr(self, rhs: u32) -> uN;
}
impl iN {
pub const unsafe fn unchecked_shl(self, rhs: u32) -> iN;
pub const unsafe fn unchecked_shr(self, rhs: u32) -> iN;
}Steps / History
- Add inherent unchecked_shl, unchecked_shr to integers #85703
-
unchecked_{shl|shr}should useu32as the RHS #103456 - Clean up unchecked_math, separate out unchecked_shifts #115626
- Add assert_unsafe_precondition to unchecked_{add,sub,neg,mul,shl,shr} methods #121571
unchecked_* (aggregate)
impl uN {
pub const unsafe fn unchecked_add(self, rhs: uN) -> uN;
pub const unsafe fn unchecked_sub(self, rhs: uN) -> uN;
pub const unsafe fn unchecked_mul(self, rhs: uN) -> uN;
pub const unsafe fn unchecked_shl(self, rhs: u32) -> uN;
pub const unsafe fn unchecked_shr(self, rhs: u32) -> uN;
}
impl iN {
pub const unsafe fn unchecked_add(self, rhs: iN) -> iN;
pub const unsafe fn unchecked_sub(self, rhs: iN) -> iN;
pub const unsafe fn unchecked_mul(self, rhs: iN) -> iN;
pub const unsafe fn unchecked_shl(self, rhs: u32) -> iN;
pub const unsafe fn unchecked_shr(self, rhs: u32) -> iN;
pub const unsafe fn unchecked_neg(self) -> iN;
}Steps / History
- Rework the std::iter::Step trait #69659 added
unchecked_{add,sub,mul} - Make unchecked_{add,sub,mul} inherent methods unstably const #85096
- Add inherent unchecked_shl, unchecked_shr to integers #85703
-
unchecked_{shl|shr}should useu32as the RHS #103456 - Clean up unchecked_math, separate out unchecked_shifts #115626 added
unchecked_neg - Stabilize
unchecked_{add,sub,mul}#122520 - Add assert_unsafe_precondition to unchecked_{add,sub,neg,mul,shl,shr} methods #121571
- Final commenting period (FCP)
- Stabilization PR
Unresolved Questions
- Should the other unchecked intrinsics like
exact_divalso get inherent versions? - From Add inherent unchecked_shl, unchecked_shr to integers #85703, consider if distinguishing the different kinds of ub could be useful (UB from overflow like
MIN/-1orMAX+1, LLVM'sn[us]w; UB from input range likex/0orx << -1; UB from lossy like2/4or3 >> 1, LLVM'sexact)
Resolved unresolved questions:
IsWe stabilisedunchecked_*the best naming for these?unchecked_{add,sub,mul}already, so, yes.
ohsayan, K4rakara, NathanSWard, jordens, markus-k and 14 more