diff --git a/library/core/src/option.rs b/library/core/src/option.rs index 0051c9eede070..18b494b3175b6 100644 --- a/library/core/src/option.rs +++ b/library/core/src/option.rs @@ -428,6 +428,37 @@ impl Option { } } + /// Returns the contained [`Some`] value, consuming the `self` value, + /// without checking that the value is not [`None`]. + /// + /// # Safety + /// + /// Undefined behavior if the value is [`None`]. + /// + /// # Examples + /// + /// ``` + /// #![feature(option_result_unwrap_unchecked)] + /// let x = Some("air"); + /// assert_eq!(unsafe { x.unwrap_unchecked() }, "air"); + /// ``` + /// + /// ```no_run + /// #![feature(option_result_unwrap_unchecked)] + /// let x: Option<&str> = None; + /// assert_eq!(unsafe { x.unwrap_unchecked() }, "air"); // Undefined behavior! + /// ``` + #[inline] + #[track_caller] + #[unstable(feature = "option_result_unwrap_unchecked", reason = "newly added", issue = "none")] + pub unsafe fn unwrap_unchecked(self) -> T { + debug_assert!(self.is_some()); + match self { + Some(val) => val, + None => unsafe { hint::unreachable_unchecked() }, + } + } + ///////////////////////////////////////////////////////////////////////// // Transforming contained values ///////////////////////////////////////////////////////////////////////// diff --git a/library/core/src/result.rs b/library/core/src/result.rs index d6d1762572928..a0f5c7746cc75 100644 --- a/library/core/src/result.rs +++ b/library/core/src/result.rs @@ -229,7 +229,7 @@ use crate::iter::{self, FromIterator, FusedIterator, TrustedLen}; use crate::ops::{self, Deref, DerefMut}; -use crate::{convert, fmt}; +use crate::{convert, fmt, hint}; /// `Result` is a type that represents either success ([`Ok`]) or failure ([`Err`]). /// @@ -821,6 +821,68 @@ impl Result { Err(e) => op(e), } } + + /// Returns the contained [`Ok`] value, consuming the `self` value, + /// without checking that the value is not an [`Err`]. + /// + /// # Safety + /// + /// Undefined behavior if the value is an [`Err`]. + /// + /// # Examples + /// + /// ``` + /// #![feature(option_result_unwrap_unchecked)] + /// let x: Result = Ok(2); + /// assert_eq!(unsafe { x.unwrap_unchecked() }, 2); + /// ``` + /// + /// ```no_run + /// #![feature(option_result_unwrap_unchecked)] + /// let x: Result = Err("emergency failure"); + /// unsafe { x.unwrap_unchecked(); } // Undefined behavior! + /// ``` + #[inline] + #[track_caller] + #[unstable(feature = "option_result_unwrap_unchecked", reason = "newly added", issue = "none")] + pub unsafe fn unwrap_unchecked(self) -> T { + debug_assert!(self.is_ok()); + match self { + Ok(t) => t, + Err(_) => unsafe { hint::unreachable_unchecked() }, + } + } + + /// Returns the contained [`Err`] value, consuming the `self` value, + /// without checking that the value is not an [`Ok`]. + /// + /// # Safety + /// + /// Undefined behavior if the value is an [`Ok`]. + /// + /// # Examples + /// + /// ```no_run + /// #![feature(option_result_unwrap_unchecked)] + /// let x: Result = Ok(2); + /// unsafe { x.unwrap_err_unchecked() }; // Undefined behavior! + /// ``` + /// + /// ``` + /// #![feature(option_result_unwrap_unchecked)] + /// let x: Result = Err("emergency failure"); + /// assert_eq!(unsafe { x.unwrap_err_unchecked() }, "emergency failure"); + /// ``` + #[inline] + #[track_caller] + #[unstable(feature = "option_result_unwrap_unchecked", reason = "newly added", issue = "none")] + pub unsafe fn unwrap_err_unchecked(self) -> E { + debug_assert!(self.is_err()); + match self { + Ok(_) => unsafe { hint::unreachable_unchecked() }, + Err(e) => e, + } + } } impl Result<&T, E> { diff --git a/library/core/tests/lib.rs b/library/core/tests/lib.rs index 98f5982fbb2c1..b7a406c30e91b 100644 --- a/library/core/tests/lib.rs +++ b/library/core/tests/lib.rs @@ -64,6 +64,7 @@ #![feature(const_raw_ptr_deref)] #![feature(never_type)] #![feature(unwrap_infallible)] +#![feature(option_result_unwrap_unchecked)] #![feature(option_unwrap_none)] #![feature(peekable_next_if)] #![feature(peekable_peek_mut)] diff --git a/library/core/tests/option.rs b/library/core/tests/option.rs index 5388b4756245a..9470451278cc4 100644 --- a/library/core/tests/option.rs +++ b/library/core/tests/option.rs @@ -160,6 +160,13 @@ fn test_unwrap_or_else() { assert_eq!(x.unwrap_or_else(|| 2), 2); } +#[test] +fn test_unwrap_unchecked() { + assert_eq!(unsafe { Some(1).unwrap_unchecked() }, 1); + let s = unsafe { Some("hello".to_string()).unwrap_unchecked() }; + assert_eq!(s, "hello"); +} + #[test] fn test_iter() { let val = 5; diff --git a/library/core/tests/result.rs b/library/core/tests/result.rs index 81660870e95e4..7aa44c6e593b3 100644 --- a/library/core/tests/result.rs +++ b/library/core/tests/result.rs @@ -119,6 +119,18 @@ pub fn test_unwrap_or_else_panic() { let _: isize = bad_err.unwrap_or_else(handler); } +#[test] +fn test_unwrap_unchecked() { + let ok: Result = Ok(100); + assert_eq!(unsafe { ok.unwrap_unchecked() }, 100); +} + +#[test] +fn test_unwrap_err_unchecked() { + let ok_err: Result = Err("Err"); + assert_eq!(unsafe { ok_err.unwrap_err_unchecked() }, "Err"); +} + #[test] pub fn test_expect_ok() { let ok: Result = Ok(100);