From a2d85a1f8b8b5c06a80d8960501ae8063151e506 Mon Sep 17 00:00:00 2001 From: Trevor Gross Date: Tue, 1 Oct 2024 17:11:48 -0400 Subject: [PATCH] Stabilize `const_option` This makes the following API stable in const contexts: impl Option { pub const fn as_mut(&mut self) -> Option<&mut T>; pub const fn expect(self, msg: &str) -> T; pub const fn unwrap(self) -> T; pub const unsafe fn unwrap_unchecked(self) -> T; pub const fn take(&mut self) -> Option; pub const fn replace(&mut self, value: T) -> Option; } impl Option<&T> { pub const fn copied(self) -> Option where T: Copy; } impl Option<&mut T> { pub const fn copied(self) -> Option where T: Copy; } impl Option> { pub const fn transpose(self) -> Result, E> } impl Option> { pub const fn flatten(self) -> Option; } The following functions make use of the unstable `const_precise_live_drops` feature: - `expect` - `unwrap` - `unwrap_unchecked` - `transpose` - `flatten` Fixes: --- alloc/src/lib.rs | 1 - core/src/array/ascii.rs | 1 - core/src/lib.rs | 1 - core/src/option.rs | 30 +++++++++++++++++++----------- core/src/ptr/non_null.rs | 2 -- core/src/time.rs | 1 - core/tests/lib.rs | 1 - 7 files changed, 19 insertions(+), 18 deletions(-) diff --git a/alloc/src/lib.rs b/alloc/src/lib.rs index 1d7b7a034541e..ec6ffa7a1059a 100644 --- a/alloc/src/lib.rs +++ b/alloc/src/lib.rs @@ -112,7 +112,6 @@ #![feature(const_eval_select)] #![feature(const_heap)] #![feature(const_maybe_uninit_write)] -#![feature(const_option)] #![feature(const_pin)] #![feature(const_size_of_val)] #![feature(const_vec_string_slice)] diff --git a/core/src/array/ascii.rs b/core/src/array/ascii.rs index 05797b042ee4a..e2faef855bc2c 100644 --- a/core/src/array/ascii.rs +++ b/core/src/array/ascii.rs @@ -9,7 +9,6 @@ impl [u8; N] { /// /// ``` /// #![feature(ascii_char)] - /// #![feature(const_option)] /// /// const HEX_DIGITS: [std::ascii::Char; 16] = /// *b"0123456789abcdef".as_ascii().unwrap(); diff --git a/core/src/lib.rs b/core/src/lib.rs index 61fe024300e2f..726aa209fdf43 100644 --- a/core/src/lib.rs +++ b/core/src/lib.rs @@ -131,7 +131,6 @@ #![feature(const_maybe_uninit_assume_init)] #![feature(const_nonnull_new)] #![feature(const_num_midpoint)] -#![feature(const_option)] #![feature(const_option_ext)] #![feature(const_pin)] #![feature(const_pointer_is_aligned)] diff --git a/core/src/option.rs b/core/src/option.rs index 154e52e288bc1..84ccb7a1f6680 100644 --- a/core/src/option.rs +++ b/core/src/option.rs @@ -723,7 +723,8 @@ impl Option { /// ``` #[inline] #[stable(feature = "rust1", since = "1.0.0")] - #[rustc_const_unstable(feature = "const_option", issue = "67441")] + #[cfg_attr(bootstrap, rustc_allow_const_fn_unstable(const_mut_refs))] + #[rustc_const_stable(feature = "const_option", since = "CURRENT_RUSTC_VERSION")] pub const fn as_mut(&mut self) -> Option<&mut T> { match *self { Some(ref mut x) => Some(x), @@ -924,7 +925,8 @@ impl Option { #[track_caller] #[stable(feature = "rust1", since = "1.0.0")] #[cfg_attr(not(test), rustc_diagnostic_item = "option_expect")] - #[rustc_const_unstable(feature = "const_option", issue = "67441")] + #[rustc_allow_const_fn_unstable(const_precise_live_drops)] + #[rustc_const_stable(feature = "const_option", since = "CURRENT_RUSTC_VERSION")] pub const fn expect(self, msg: &str) -> T { match self { Some(val) => val, @@ -962,7 +964,8 @@ impl Option { #[track_caller] #[stable(feature = "rust1", since = "1.0.0")] #[cfg_attr(not(test), rustc_diagnostic_item = "option_unwrap")] - #[rustc_const_unstable(feature = "const_option", issue = "67441")] + #[rustc_allow_const_fn_unstable(const_precise_live_drops)] + #[rustc_const_stable(feature = "const_option", since = "CURRENT_RUSTC_VERSION")] pub const fn unwrap(self) -> T { match self { Some(val) => val, @@ -1069,7 +1072,8 @@ impl Option { #[inline] #[track_caller] #[stable(feature = "option_result_unwrap_unchecked", since = "1.58.0")] - #[rustc_const_unstable(feature = "const_option", issue = "67441")] + #[rustc_allow_const_fn_unstable(const_precise_live_drops)] + #[rustc_const_stable(feature = "const_option", since = "CURRENT_RUSTC_VERSION")] pub const unsafe fn unwrap_unchecked(self) -> T { match self { Some(val) => val, @@ -1712,7 +1716,8 @@ impl Option { /// ``` #[inline] #[stable(feature = "rust1", since = "1.0.0")] - #[rustc_const_unstable(feature = "const_option", issue = "67441")] + #[cfg_attr(bootstrap, rustc_allow_const_fn_unstable(const_mut_refs))] + #[rustc_const_stable(feature = "const_option", since = "CURRENT_RUSTC_VERSION")] pub const fn take(&mut self) -> Option { // FIXME(const-hack) replace `mem::replace` by `mem::take` when the latter is const ready mem::replace(self, None) @@ -1769,8 +1774,9 @@ impl Option { /// assert_eq!(old, None); /// ``` #[inline] - #[rustc_const_unstable(feature = "const_option", issue = "67441")] #[stable(feature = "option_replace", since = "1.31.0")] + #[cfg_attr(bootstrap, rustc_allow_const_fn_unstable(const_mut_refs))] + #[rustc_const_stable(feature = "const_option", since = "CURRENT_RUSTC_VERSION")] pub const fn replace(&mut self, value: T) -> Option { mem::replace(self, Some(value)) } @@ -1878,7 +1884,7 @@ impl Option<&T> { /// ``` #[must_use = "`self` will be dropped if the result is not used"] #[stable(feature = "copied", since = "1.35.0")] - #[rustc_const_unstable(feature = "const_option", issue = "67441")] + #[rustc_const_stable(feature = "const_option", since = "CURRENT_RUSTC_VERSION")] pub const fn copied(self) -> Option where T: Copy, @@ -1931,7 +1937,8 @@ impl Option<&mut T> { /// ``` #[must_use = "`self` will be dropped if the result is not used"] #[stable(feature = "copied", since = "1.35.0")] - #[rustc_const_unstable(feature = "const_option", issue = "67441")] + #[cfg_attr(bootstrap, rustc_allow_const_fn_unstable(const_mut_refs))] + #[rustc_const_stable(feature = "const_option", since = "CURRENT_RUSTC_VERSION")] pub const fn copied(self) -> Option where T: Copy, @@ -1986,7 +1993,8 @@ impl Option> { /// ``` #[inline] #[stable(feature = "transpose_result", since = "1.33.0")] - #[rustc_const_unstable(feature = "const_option", issue = "67441")] + #[rustc_allow_const_fn_unstable(const_precise_live_drops)] + #[rustc_const_stable(feature = "const_option", since = "CURRENT_RUSTC_VERSION")] pub const fn transpose(self) -> Result, E> { match self { Some(Ok(x)) => Ok(Some(x)), @@ -2009,7 +2017,6 @@ const fn unwrap_failed() -> ! { #[cfg_attr(feature = "panic_immediate_abort", inline)] #[cold] #[track_caller] -#[rustc_const_unstable(feature = "const_option", issue = "67441")] const fn expect_failed(msg: &str) -> ! { panic_display(&msg) } @@ -2534,7 +2541,8 @@ impl Option> { /// ``` #[inline] #[stable(feature = "option_flattening", since = "1.40.0")] - #[rustc_const_unstable(feature = "const_option", issue = "67441")] + #[rustc_allow_const_fn_unstable(const_precise_live_drops)] + #[rustc_const_stable(feature = "const_option", since = "CURRENT_RUSTC_VERSION")] pub const fn flatten(self) -> Option { // FIXME(const-hack): could be written with `and_then` match self { diff --git a/core/src/ptr/non_null.rs b/core/src/ptr/non_null.rs index dc1a7c6220ebe..980d4a3cf6ceb 100644 --- a/core/src/ptr/non_null.rs +++ b/core/src/ptr/non_null.rs @@ -1211,7 +1211,6 @@ impl NonNull { /// /// ``` /// #![feature(const_nonnull_new)] - /// #![feature(const_option)] /// #![feature(const_pointer_is_aligned)] /// use std::ptr::NonNull; /// @@ -1264,7 +1263,6 @@ impl NonNull { /// /// ``` /// #![feature(const_pointer_is_aligned)] - /// #![feature(const_option)] /// #![feature(const_nonnull_new)] /// use std::ptr::NonNull; /// diff --git a/core/src/time.rs b/core/src/time.rs index a997874dd9c7b..f7ea7e06e9cdb 100644 --- a/core/src/time.rs +++ b/core/src/time.rs @@ -626,7 +626,6 @@ impl Duration { /// ``` #[stable(feature = "duration_abs_diff", since = "1.81.0")] #[rustc_const_stable(feature = "duration_abs_diff", since = "1.81.0")] - #[rustc_allow_const_fn_unstable(const_option)] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] diff --git a/core/tests/lib.rs b/core/tests/lib.rs index 02777886b45a3..9e15bb1dd8fcb 100644 --- a/core/tests/lib.rs +++ b/core/tests/lib.rs @@ -24,7 +24,6 @@ #![feature(const_ipv6)] #![feature(const_likely)] #![feature(const_nonnull_new)] -#![feature(const_option)] #![feature(const_option_ext)] #![feature(const_pin)] #![feature(const_pointer_is_aligned)]