Rollup merge of rust-lang#76543 - ssomers:btree_cleanup_4, r=Mark-Simulacrum

tmandry · web-flow · commit dd4627abc1db · 2020-09-09T20:07:22.000-07:00
Document btree's unwrap_unchecked rust-lang#74693's second wind
diff --git a/library/alloc/src/collections/btree/mod.rs b/library/alloc/src/collections/btree/mod.rs
@@ -13,6 +13,9 @@ trait Recover<Q: ?Sized> {
     fn replace(&mut self, key: Self::Key) -> Option<Self::Key>;
 }
 
+/// Same purpose as `Option::unwrap` but doesn't always guarantee a panic
+/// if the option contains no value.
+/// SAFETY: the caller must ensure that the option contains a value.
 #[inline(always)]
 pub unsafe fn unwrap_unchecked<T>(val: Option<T>) -> T {
     val.unwrap_or_else(|| {

Original file line number	Diff line number	Diff line change
`@@ -13,6 +13,9 @@ trait Recover<Q: ?Sized> {`
`13`	`13`	`fn replace(&mut self, key: Self::Key) -> Option<Self::Key>;`
`14`	`14`	`}`
`15`	`15`
	`16`	+/// Same purpose as `Option::unwrap` but doesn't always guarantee a panic
	`17`	`+/// if the option contains no value.`
	`18`	`+/// SAFETY: the caller must ensure that the option contains a value.`
`16`	`19`	`#[inline(always)]`
`17`	`20`	`pub unsafe fn unwrap_unchecked<T>(val: Option<T>) -> T {`
`18`	`21`	`val.unwrap_or_else(\|\| {`