diff options
| -rw-r--r-- | library/core/src/result.rs | 137 | ||||
| -rw-r--r-- | library/coretests/tests/lib.rs | 2 | ||||
| -rw-r--r-- | library/coretests/tests/result.rs | 83 |
3 files changed, 197 insertions, 25 deletions
diff --git a/library/core/src/result.rs b/library/core/src/result.rs index f65257ff59b..812fc0d9819 100644 --- a/library/core/src/result.rs +++ b/library/core/src/result.rs @@ -534,6 +534,7 @@ #![stable(feature = "rust1", since = "1.0.0")] use crate::iter::{self, FusedIterator, TrustedLen}; +use crate::marker::Destruct; use crate::ops::{self, ControlFlow, Deref, DerefMut}; use crate::{convert, fmt, hint}; @@ -606,7 +607,13 @@ impl<T, E> Result<T, E> { #[must_use] #[inline] #[stable(feature = "is_some_and", since = "1.70.0")] - pub fn is_ok_and(self, f: impl FnOnce(T) -> bool) -> bool { + #[rustc_const_unstable(feature = "const_result_trait_fn", issue = "144211")] + pub const fn is_ok_and<F>(self, f: F) -> bool + where + F: ~const FnOnce(T) -> bool + ~const Destruct, + T: ~const Destruct, + E: ~const Destruct, + { match self { Err(_) => false, Ok(x) => f(x), @@ -655,7 +662,13 @@ impl<T, E> Result<T, E> { #[must_use] #[inline] #[stable(feature = "is_some_and", since = "1.70.0")] - pub fn is_err_and(self, f: impl FnOnce(E) -> bool) -> bool { + #[rustc_const_unstable(feature = "const_result_trait_fn", issue = "144211")] + pub const fn is_err_and<F>(self, f: F) -> bool + where + F: ~const FnOnce(E) -> bool + ~const Destruct, + E: ~const Destruct, + T: ~const Destruct, + { match self { Ok(_) => false, Err(e) => f(e), @@ -682,8 +695,13 @@ impl<T, E> Result<T, E> { /// ``` #[inline] #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_unstable(feature = "const_result_trait_fn", issue = "144211")] #[rustc_diagnostic_item = "result_ok_method"] - pub fn ok(self) -> Option<T> { + pub const fn ok(self) -> Option<T> + where + T: ~const Destruct, + E: ~const Destruct, + { match self { Ok(x) => Some(x), Err(_) => None, @@ -706,7 +724,12 @@ impl<T, E> Result<T, E> { /// ``` #[inline] #[stable(feature = "rust1", since = "1.0.0")] - pub fn err(self) -> Option<E> { + #[rustc_const_unstable(feature = "const_result_trait_fn", issue = "144211")] + pub const fn err(self) -> Option<E> + where + T: ~const Destruct, + E: ~const Destruct, + { match self { Ok(_) => None, Err(x) => Some(x), @@ -796,7 +819,11 @@ impl<T, E> Result<T, E> { /// ``` #[inline] #[stable(feature = "rust1", since = "1.0.0")] - pub fn map<U, F: FnOnce(T) -> U>(self, op: F) -> Result<U, E> { + #[rustc_const_unstable(feature = "const_result_trait_fn", issue = "144211")] + pub const fn map<U, F>(self, op: F) -> Result<U, E> + where + F: ~const FnOnce(T) -> U + ~const Destruct, + { match self { Ok(t) => Ok(op(t)), Err(e) => Err(e), @@ -823,8 +850,15 @@ impl<T, E> Result<T, E> { /// ``` #[inline] #[stable(feature = "result_map_or", since = "1.41.0")] + #[rustc_const_unstable(feature = "const_result_trait_fn", issue = "144211")] #[must_use = "if you don't need the returned value, use `if let` instead"] - pub fn map_or<U, F: FnOnce(T) -> U>(self, default: U, f: F) -> U { + pub const fn map_or<U, F>(self, default: U, f: F) -> U + where + F: ~const FnOnce(T) -> U + ~const Destruct, + T: ~const Destruct, + E: ~const Destruct, + U: ~const Destruct, + { match self { Ok(t) => f(t), Err(_) => default, @@ -851,7 +885,12 @@ impl<T, E> Result<T, E> { /// ``` #[inline] #[stable(feature = "result_map_or_else", since = "1.41.0")] - pub fn map_or_else<U, D: FnOnce(E) -> U, F: FnOnce(T) -> U>(self, default: D, f: F) -> U { + #[rustc_const_unstable(feature = "const_result_trait_fn", issue = "144211")] + pub const fn map_or_else<U, D, F>(self, default: D, f: F) -> U + where + D: ~const FnOnce(E) -> U + ~const Destruct, + F: ~const FnOnce(T) -> U + ~const Destruct, + { match self { Ok(t) => f(t), Err(e) => default(e), @@ -877,10 +916,13 @@ impl<T, E> Result<T, E> { /// [default value]: Default::default #[inline] #[unstable(feature = "result_option_map_or_default", issue = "138099")] - pub fn map_or_default<U, F>(self, f: F) -> U + #[rustc_const_unstable(feature = "const_result_trait_fn", issue = "144211")] + pub const fn map_or_default<U, F>(self, f: F) -> U where - U: Default, - F: FnOnce(T) -> U, + F: ~const FnOnce(T) -> U + ~const Destruct, + U: ~const Default, + T: ~const Destruct, + E: ~const Destruct, { match self { Ok(t) => f(t), @@ -908,7 +950,11 @@ impl<T, E> Result<T, E> { /// ``` #[inline] #[stable(feature = "rust1", since = "1.0.0")] - pub fn map_err<F, O: FnOnce(E) -> F>(self, op: O) -> Result<T, F> { + #[rustc_const_unstable(feature = "const_result_trait_fn", issue = "144211")] + pub const fn map_err<F, O>(self, op: O) -> Result<T, F> + where + O: ~const FnOnce(E) -> F + ~const Destruct, + { match self { Ok(t) => Ok(t), Err(e) => Err(op(e)), @@ -930,7 +976,11 @@ impl<T, E> Result<T, E> { /// ``` #[inline] #[stable(feature = "result_option_inspect", since = "1.76.0")] - pub fn inspect<F: FnOnce(&T)>(self, f: F) -> Self { + #[rustc_const_unstable(feature = "const_result_trait_fn", issue = "144211")] + pub const fn inspect<F>(self, f: F) -> Self + where + F: ~const FnOnce(&T) + ~const Destruct, + { if let Ok(ref t) = self { f(t); } @@ -954,7 +1004,11 @@ impl<T, E> Result<T, E> { /// ``` #[inline] #[stable(feature = "result_option_inspect", since = "1.76.0")] - pub fn inspect_err<F: FnOnce(&E)>(self, f: F) -> Self { + #[rustc_const_unstable(feature = "const_result_trait_fn", issue = "144211")] + pub const fn inspect_err<F>(self, f: F) -> Self + where + F: ~const FnOnce(&E) + ~const Destruct, + { if let Err(ref e) = self { f(e); } @@ -1033,7 +1087,8 @@ impl<T, E> Result<T, E> { /// ``` #[inline] #[stable(feature = "rust1", since = "1.0.0")] - pub fn iter(&self) -> Iter<'_, T> { + #[rustc_const_unstable(feature = "const_result_trait_fn", issue = "144211")] + pub const fn iter(&self) -> Iter<'_, T> { Iter { inner: self.as_ref().ok() } } @@ -1056,7 +1111,8 @@ impl<T, E> Result<T, E> { /// ``` #[inline] #[stable(feature = "rust1", since = "1.0.0")] - pub fn iter_mut(&mut self) -> IterMut<'_, T> { + #[rustc_const_unstable(feature = "const_result_trait_fn", issue = "144211")] + pub const fn iter_mut(&mut self) -> IterMut<'_, T> { IterMut { inner: self.as_mut().ok() } } @@ -1195,9 +1251,11 @@ impl<T, E> Result<T, E> { /// [`FromStr`]: crate::str::FromStr #[inline] #[stable(feature = "result_unwrap_or_default", since = "1.16.0")] - pub fn unwrap_or_default(self) -> T + #[rustc_const_unstable(feature = "const_result_trait_fn", issue = "144211")] + pub const fn unwrap_or_default(self) -> T where - T: Default, + T: ~const Default + ~const Destruct, + E: ~const Destruct, { match self { Ok(x) => x, @@ -1370,7 +1428,13 @@ impl<T, E> Result<T, E> { /// ``` #[inline] #[stable(feature = "rust1", since = "1.0.0")] - pub fn and<U>(self, res: Result<U, E>) -> Result<U, E> { + #[rustc_const_unstable(feature = "const_result_trait_fn", issue = "144211")] + pub const fn and<U>(self, res: Result<U, E>) -> Result<U, E> + where + T: ~const Destruct, + E: ~const Destruct, + U: ~const Destruct, + { match self { Ok(_) => res, Err(e) => Err(e), @@ -1409,8 +1473,12 @@ impl<T, E> Result<T, E> { /// ``` #[inline] #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_unstable(feature = "const_result_trait_fn", issue = "144211")] #[rustc_confusables("flat_map", "flatmap")] - pub fn and_then<U, F: FnOnce(T) -> Result<U, E>>(self, op: F) -> Result<U, E> { + pub const fn and_then<U, F>(self, op: F) -> Result<U, E> + where + F: ~const FnOnce(T) -> Result<U, E> + ~const Destruct, + { match self { Ok(t) => op(t), Err(e) => Err(e), @@ -1446,7 +1514,13 @@ impl<T, E> Result<T, E> { /// ``` #[inline] #[stable(feature = "rust1", since = "1.0.0")] - pub fn or<F>(self, res: Result<T, F>) -> Result<T, F> { + #[rustc_const_unstable(feature = "const_result_trait_fn", issue = "144211")] + pub const fn or<F>(self, res: Result<T, F>) -> Result<T, F> + where + T: ~const Destruct, + E: ~const Destruct, + F: ~const Destruct, + { match self { Ok(v) => Ok(v), Err(_) => res, @@ -1471,7 +1545,11 @@ impl<T, E> Result<T, E> { /// ``` #[inline] #[stable(feature = "rust1", since = "1.0.0")] - pub fn or_else<F, O: FnOnce(E) -> Result<T, F>>(self, op: O) -> Result<T, F> { + #[rustc_const_unstable(feature = "const_result_trait_fn", issue = "144211")] + pub const fn or_else<F, O>(self, op: O) -> Result<T, F> + where + O: ~const FnOnce(E) -> Result<T, F> + ~const Destruct, + { match self { Ok(t) => Ok(t), Err(e) => op(e), @@ -1498,7 +1576,12 @@ impl<T, E> Result<T, E> { /// ``` #[inline] #[stable(feature = "rust1", since = "1.0.0")] - pub fn unwrap_or(self, default: T) -> T { + #[rustc_const_unstable(feature = "const_result_trait_fn", issue = "144211")] + pub const fn unwrap_or(self, default: T) -> T + where + T: ~const Destruct, + E: ~const Destruct, + { match self { Ok(t) => t, Err(_) => default, @@ -1519,7 +1602,11 @@ impl<T, E> Result<T, E> { #[inline] #[track_caller] #[stable(feature = "rust1", since = "1.0.0")] - pub fn unwrap_or_else<F: FnOnce(E) -> T>(self, op: F) -> T { + #[rustc_const_unstable(feature = "const_result_trait_fn", issue = "144211")] + pub const fn unwrap_or_else<F>(self, op: F) -> T + where + F: ~const FnOnce(E) -> T + ~const Destruct, + { match self { Ok(t) => t, Err(e) => op(e), @@ -1762,7 +1849,7 @@ impl<T, E> Result<Result<T, E>, E> { #[cold] #[track_caller] fn unwrap_failed(msg: &str, error: &dyn fmt::Debug) -> ! { - panic!("{msg}: {error:?}") + panic!("{msg}: {error:?}"); } // This is a separate function to avoid constructing a `dyn Debug` @@ -1773,7 +1860,7 @@ fn unwrap_failed(msg: &str, error: &dyn fmt::Debug) -> ! { #[inline] #[cold] #[track_caller] -fn unwrap_failed<T>(_msg: &str, _error: &T) -> ! { +const fn unwrap_failed<T>(_msg: &str, _error: &T) -> ! { panic!() } diff --git a/library/coretests/tests/lib.rs b/library/coretests/tests/lib.rs index 029a7b00ad3..0a9c0c61c95 100644 --- a/library/coretests/tests/lib.rs +++ b/library/coretests/tests/lib.rs @@ -20,6 +20,7 @@ #![feature(const_eval_select)] #![feature(const_ops)] #![feature(const_ref_cell)] +#![feature(const_result_trait_fn)] #![feature(const_trait_impl)] #![feature(core_float_math)] #![feature(core_intrinsics)] @@ -82,6 +83,7 @@ #![feature(pointer_is_aligned_to)] #![feature(portable_simd)] #![feature(ptr_metadata)] +#![feature(result_option_map_or_default)] #![feature(slice_from_ptr_range)] #![feature(slice_internals)] #![feature(slice_partition_dedup)] diff --git a/library/coretests/tests/result.rs b/library/coretests/tests/result.rs index 90ec844bc57..39898d5dbb7 100644 --- a/library/coretests/tests/result.rs +++ b/library/coretests/tests/result.rs @@ -421,3 +421,86 @@ fn result_try_trait_v2_branch() { assert_eq!(Ok::<NonZero<u32>, ()>(one).branch(), Continue(one)); assert_eq!(Err::<NonZero<u32>, ()>(()).branch(), Break(Err(()))); } + +// helper functions for const contexts +const fn eq10(x: u8) -> bool { + x == 10 +} +const fn eq20(e: u8) -> bool { + e == 20 +} +const fn double_u16(x: u8) -> u16 { + x as u16 * 2 +} +const fn to_u16(x: u8) -> u16 { + x as u16 +} +const fn err_to_u16_plus1(e: u8) -> u16 { + e as u16 + 1 +} +const fn inc_u8(x: u8) -> u8 { + x + 1 +} +const fn noop_u8_ref(_x: &u8) {} +const fn add1_result(x: u8) -> Result<u8, u8> { + Ok(x + 1) +} +const fn add5_result(e: u8) -> Result<u8, u8> { + Ok(e + 5) +} +const fn plus7_u8(e: u8) -> u8 { + e + 7 +} + +#[test] +fn test_const_result() { + const { + let r_ok: Result<u8, u8> = Ok(10); + let r_err: Result<u8, u8> = Err(20); + assert!(r_ok.is_ok()); + assert!(r_err.is_err()); + + let ok_and = r_ok.is_ok_and(eq10); + let err_and = r_err.is_err_and(eq20); + assert!(ok_and); + assert!(err_and); + + let opt_ok: Option<u8> = r_ok.ok(); + let opt_err: Option<u8> = r_err.err(); + assert!(opt_ok.unwrap() == 10); + assert!(opt_err.unwrap() == 20); + + let mapped: Result<u16, u8> = r_ok.map(double_u16); + let map_or: u16 = r_ok.map_or(0, to_u16); + let map_or_else: u16 = r_err.map_or_else(err_to_u16_plus1, to_u16); + let map_or_default: u8 = r_err.map_or_default(inc_u8); + assert!(mapped.unwrap_or_default() == 20); + assert!(map_or == 10); + assert!(map_or_else == 21); + assert!(map_or_default == 0); + + let _map_err: Result<u8, u16> = r_err.map_err(to_u16); + //FIXME: currently can't unwrap const error + // assert!(map_err.unwrap_err() == 20); + + let inspected_ok: Result<u8, u8> = r_ok.inspect(noop_u8_ref); + let inspected_err: Result<u8, u8> = r_err.inspect_err(noop_u8_ref); + assert!(inspected_ok.is_ok()); + assert!(inspected_err.is_err()); + + let unwrapped_default: u8 = r_err.unwrap_or_default(); + assert!(unwrapped_default == 0); + + let and_then: Result<u8, u8> = r_ok.and_then(add1_result); + let or: Result<u8, u8> = r_err.or(Ok(5)); + let or_else: Result<u8, u8> = r_err.or_else(add5_result); + assert!(and_then.unwrap_or_default() == 11); + assert!(or.unwrap_or_default() == 5); + assert!(or_else.unwrap_or_default() == 25); + + let u_or: u8 = r_err.unwrap_or(7); + let u_or_else: u8 = r_err.unwrap_or_else(plus7_u8); + assert!(u_or == 7); + assert!(u_or_else == 27); + }; +} |