From 5fe0bb743a0af0413f8989a70a4f926fa5c63074 Mon Sep 17 00:00:00 2001 From: Aaron Turon Date: Fri, 20 Mar 2015 10:22:57 -0700 Subject: [PATCH] Future-proof indexing on maps: remove IndexMut This commit removes the `IndexMut` impls on `HashMap` and `BTreeMap`, in order to future-proof the API against the eventual inclusion of an `IndexSet` trait. Ideally, we would eventually be able to support: ```rust map[owned_key] = val; map[borrowed_key].mutating_method(arguments); &mut map[borrowed_key]; ``` but to keep the design space as unconstrained as possible, we do not currently want to support `IndexMut`, in case some other strategy will eventually be needed. Code currently using mutating index notation can use `get_mut` instead. [breaking-change] Closes #23448 --- src/libcollections/btree/map.rs | 11 +---------- src/librustc_resolve/lib.rs | 2 +- src/librustc_resolve/resolve_imports.rs | 2 +- src/librustc_typeck/check/upvar.rs | 2 +- src/libstd/collections/hash/map.rs | 14 +------------- 5 files changed, 5 insertions(+), 26 deletions(-) diff --git a/src/libcollections/btree/map.rs b/src/libcollections/btree/map.rs index c7e1e3c91766e..a9e1ce8d7ce50 100644 --- a/src/libcollections/btree/map.rs +++ b/src/libcollections/btree/map.rs @@ -24,7 +24,7 @@ use core::default::Default; use core::fmt::Debug; use core::hash::{Hash, Hasher}; use core::iter::{Map, FromIterator, IntoIterator}; -use core::ops::{Index, IndexMut}; +use core::ops::{Index}; use core::{iter, fmt, mem, usize}; use Bound::{self, Included, Excluded, Unbounded}; @@ -925,15 +925,6 @@ impl Index for BTreeMap } } -#[stable(feature = "rust1", since = "1.0.0")] -impl IndexMut for BTreeMap - where K: Borrow, Q: Ord -{ - fn index_mut(&mut self, key: &Q) -> &mut V { - self.get_mut(key).expect("no entry found for key") - } -} - /// Genericises over how to get the correct type of iterator from the correct type /// of Node ownership. trait Traverse { diff --git a/src/librustc_resolve/lib.rs b/src/librustc_resolve/lib.rs index b619c6a77d009..566af2590e6c0 100644 --- a/src/librustc_resolve/lib.rs +++ b/src/librustc_resolve/lib.rs @@ -900,7 +900,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> { return; } if self.glob_map.contains_key(&import_id) { - self.glob_map[import_id].insert(name); + self.glob_map.get_mut(&import_id).unwrap().insert(name); return; } diff --git a/src/librustc_resolve/resolve_imports.rs b/src/librustc_resolve/resolve_imports.rs index 737ec71cab3da..46451019760dd 100644 --- a/src/librustc_resolve/resolve_imports.rs +++ b/src/librustc_resolve/resolve_imports.rs @@ -603,7 +603,7 @@ impl<'a, 'b:'a, 'tcx:'b> ImportResolver<'a, 'b, 'tcx> { // We've successfully resolved the import. Write the results in. let mut import_resolutions = module_.import_resolutions.borrow_mut(); - let import_resolution = &mut (*import_resolutions)[target]; + let import_resolution = import_resolutions.get_mut(&target).unwrap(); { let mut check_and_write_import = |namespace, result: &_, used_public: &mut bool| { diff --git a/src/librustc_typeck/check/upvar.rs b/src/librustc_typeck/check/upvar.rs index 09592db8a116d..ce4bb4465517b 100644 --- a/src/librustc_typeck/check/upvar.rs +++ b/src/librustc_typeck/check/upvar.rs @@ -380,7 +380,7 @@ impl<'a,'tcx> AdjustBorrowKind<'a,'tcx> { // borrow_kind of the upvar to make sure it // is inferred to mutable if necessary let mut upvar_capture_map = self.fcx.inh.upvar_capture_map.borrow_mut(); - let ub = &mut upvar_capture_map[upvar_id]; + let ub = upvar_capture_map.get_mut(&upvar_id).unwrap(); self.adjust_upvar_borrow_kind(upvar_id, ub, borrow_kind); // also need to be in an FnMut closure since this is not an ImmBorrow diff --git a/src/libstd/collections/hash/map.rs b/src/libstd/collections/hash/map.rs index 60b1738d2c989..9139e182ce479 100644 --- a/src/libstd/collections/hash/map.rs +++ b/src/libstd/collections/hash/map.rs @@ -23,7 +23,7 @@ use hash::{Hash, SipHasher}; use iter::{self, Iterator, ExactSizeIterator, IntoIterator, IteratorExt, FromIterator, Extend, Map}; use marker::Sized; use mem::{self, replace}; -use ops::{Deref, FnMut, Index, IndexMut}; +use ops::{Deref, FnMut, Index}; use option::Option::{self, Some, None}; use rand::{self, Rng}; use result::Result::{self, Ok, Err}; @@ -1258,18 +1258,6 @@ impl Index for HashMap } } -#[stable(feature = "rust1", since = "1.0.0")] -impl IndexMut for HashMap - where K: Eq + Hash + Borrow, - Q: Eq + Hash, - S: HashState, -{ - #[inline] - fn index_mut<'a>(&'a mut self, index: &Q) -> &'a mut V { - self.get_mut(index).expect("no entry found for key") - } -} - /// HashMap iterator. #[stable(feature = "rust1", since = "1.0.0")] pub struct Iter<'a, K: 'a, V: 'a> {