diff options
| -rw-r--r-- | compiler/rustc_mir/src/lib.rs | 1 | ||||
| -rw-r--r-- | compiler/rustc_mir/src/transform/coverage/graph.rs | 5 | ||||
| -rw-r--r-- | library/core/src/option.rs | 28 |
3 files changed, 30 insertions, 4 deletions
diff --git a/compiler/rustc_mir/src/lib.rs b/compiler/rustc_mir/src/lib.rs index 508510a81e1..bbfcec5a76a 100644 --- a/compiler/rustc_mir/src/lib.rs +++ b/compiler/rustc_mir/src/lib.rs @@ -25,6 +25,7 @@ Rust MIR: a lowered representation of Rust. #![feature(stmt_expr_attributes)] #![feature(trait_alias)] #![feature(option_expect_none)] +#![feature(option_get_or_default)] #![feature(or_patterns)] #![feature(once_cell)] #![feature(control_flow_enum)] diff --git a/compiler/rustc_mir/src/transform/coverage/graph.rs b/compiler/rustc_mir/src/transform/coverage/graph.rs index e58b915f126..8ad0d133b17 100644 --- a/compiler/rustc_mir/src/transform/coverage/graph.rs +++ b/compiler/rustc_mir/src/transform/coverage/graph.rs @@ -392,10 +392,7 @@ impl BasicCoverageBlockData { } } let operand = counter_kind.as_operand_id(); - if let Some(replaced) = self - .edge_from_bcbs - .get_or_insert_with(FxHashMap::default) - .insert(from_bcb, counter_kind) + if let Some(replaced) = self.edge_from_bcbs.get_or_default().insert(from_bcb, counter_kind) { Error::from_string(format!( "attempt to set an edge counter more than once; from_bcb: \ diff --git a/library/core/src/option.rs b/library/core/src/option.rs index e3c812a047c..9478e7f06bd 100644 --- a/library/core/src/option.rs +++ b/library/core/src/option.rs @@ -854,6 +854,34 @@ impl<T> Option<T> { // Entry-like operations to insert if None and return a reference ///////////////////////////////////////////////////////////////////////// + /// Inserts the default value into the option if it is [`None`], then + /// returns a mutable reference to the contained value. + /// + /// # Examples + /// + /// ``` + /// #![feature(option_get_or_default)] + /// + /// let mut x = None; + /// + /// { + /// let y: &mut u32 = x.get_or_default(); + /// assert_eq!(y, &0); + /// + /// *y = 7; + /// } + /// + /// assert_eq!(x, Some(7)); + /// ``` + #[inline] + #[unstable(feature = "option_get_or_default", issue = "82901")] + pub fn get_or_default(&mut self) -> &mut T + where + T: Default, + { + self.get_or_insert_with(Default::default) + } + /// Inserts `value` into the option if it is [`None`], then /// returns a mutable reference to the contained value. /// |