rollup merge of #20653: alexcrichton/entry-unstable

There's been some debate over the precise form that these APIs should take, and
they've undergone some changes recently, so these APIs are going to be left
unstable for now to be fleshed out during the next release cycle.

Author: alexcrichton

src/libcollections/btree/map.rs

@@ -19,7 +19,7 @@ pub use self::Entry::*;
 
 use core::prelude::*;
 
-use core::borrow::{BorrowFrom, ToOwned};
+use core::borrow::BorrowFrom;
 use core::cmp::Ordering;
 use core::default::Default;
 use core::fmt::Show;
@@ -128,24 +128,24 @@ pub struct Values<'a, K: 'a, V: 'a> {
     inner: Map<(&'a K, &'a V), &'a V, Iter<'a, K, V>, fn((&'a K, &'a V)) -> &'a V>
 }
 
-#[stable]
 /// A view into a single entry in a map, which may either be vacant or occupied.
-pub enum Entry<'a, Q: ?Sized +'a, K:'a, V:'a> {
+#[unstable = "precise API still under development"]
+pub enum Entry<'a, K:'a, V:'a> {
     /// A vacant Entry
-    Vacant(VacantEntry<'a, Q, K, V>),
+    Vacant(VacantEntry<'a, K, V>),
     /// An occupied Entry
     Occupied(OccupiedEntry<'a, K, V>),
 }
 
-#[stable]
 /// A vacant Entry.
-pub struct VacantEntry<'a, Q: ?Sized +'a, K:'a, V:'a> {
-    key: &'a Q,
+#[unstable = "precise API still under development"]
+pub struct VacantEntry<'a, K:'a, V:'a> {
+    key: K,
     stack: stack::SearchStack<'a, K, V, node::handle::Edge, node::handle::Leaf>,
 }
 
-#[stable]
 /// An occupied Entry.
+#[unstable = "precise API still under development"]
 pub struct OccupiedEntry<'a, K:'a, V:'a> {
     stack: stack::SearchStack<'a, K, V, node::handle::KV, node::handle::LeafOrInternal>,
 }
@@ -1111,55 +1111,55 @@ impl<'a, K, V> DoubleEndedIterator for Values<'a, K, V> {
 #[stable]
 impl<'a, K, V> ExactSizeIterator for Values<'a, K, V> {}
 
-impl<'a, Q: ?Sized, K: Ord, V> Entry<'a, Q, K, V> {
+impl<'a, K: Ord, V> Entry<'a, K, V> {
     #[unstable = "matches collection reform v2 specification, waiting for dust to settle"]
     /// Returns a mutable reference to the entry if occupied, or the VacantEntry if vacant
-    pub fn get(self) -> Result<&'a mut V, VacantEntry<'a, Q, K, V>> {
+    pub fn get(self) -> Result<&'a mut V, VacantEntry<'a, K, V>> {
         match self {
             Occupied(entry) => Ok(entry.into_mut()),
             Vacant(entry) => Err(entry),
         }
     }
 }
 
-impl<'a, Q: ?Sized + ToOwned<K>, K: Ord, V> VacantEntry<'a, Q, K, V> {
-    #[stable]
+impl<'a, K: Ord, V> VacantEntry<'a, K, V> {
     /// Sets the value of the entry with the VacantEntry's key,
     /// and returns a mutable reference to it.
+    #[unstable = "matches collection reform v2 specification, waiting for dust to settle"]
     pub fn insert(self, value: V) -> &'a mut V {
-        self.stack.insert(self.key.to_owned(), value)
+        self.stack.insert(self.key, value)
     }
 }
 
 impl<'a, K: Ord, V> OccupiedEntry<'a, K, V> {
-    #[stable]
     /// Gets a reference to the value in the entry.
+    #[unstable = "matches collection reform v2 specification, waiting for dust to settle"]
     pub fn get(&self) -> &V {
         self.stack.peek()
     }
 
-    #[stable]
     /// Gets a mutable reference to the value in the entry.
+    #[unstable = "matches collection reform v2 specification, waiting for dust to settle"]
     pub fn get_mut(&mut self) -> &mut V {
         self.stack.peek_mut()
     }
 
-    #[stable]
     /// Converts the entry into a mutable reference to its value.
+    #[unstable = "matches collection reform v2 specification, waiting for dust to settle"]
     pub fn into_mut(self) -> &'a mut V {
         self.stack.into_top()
     }
 
-    #[stable]
     /// Sets the value of the entry with the OccupiedEntry's key,
     /// and returns the entry's old value.
+    #[unstable = "matches collection reform v2 specification, waiting for dust to settle"]
     pub fn insert(&mut self, mut value: V) -> V {
         mem::swap(self.stack.peek_mut(), &mut value);
         value
     }
 
-    #[stable]
     /// Takes the value of the entry out of the map, and returns it.
+    #[unstable = "matches collection reform v2 specification, waiting for dust to settle"]
     pub fn remove(self) -> V {
         self.stack.remove()
     }
@@ -1361,15 +1361,13 @@ impl<K: Ord, V> BTreeMap<K, V> {
     /// assert_eq!(count["a"], 3u);
     /// ```
     /// The key must have the same ordering before or after `.to_owned()` is called.
-    #[stable]
-    pub fn entry<'a, Q: ?Sized>(&'a mut self, mut key: &'a Q) -> Entry<'a, Q, K, V>
-        where Q: Ord + ToOwned<K>
-    {
+    #[unstable = "precise API still under development"]
+    pub fn entry<'a>(&'a mut self, mut key: K) -> Entry<'a, K, V> {
         // same basic logic of `swap` and `pop`, blended together
         let mut stack = stack::PartialSearchStack::new(self);
         loop {
             let result = stack.with(move |pusher, node| {
-                return match Node::search(node, key) {
+                return match Node::search(node, &key) {
                     Found(handle) => {
                         // Perfect match
                         Finished(Occupied(OccupiedEntry {
@@ -1412,7 +1410,7 @@ impl<K: Ord, V> BTreeMap<K, V> {
 #[cfg(test)]
 mod test {
     use prelude::*;
-    use std::borrow::{ToOwned, BorrowFrom};
+    use std::borrow::BorrowFrom;
 
     use super::{BTreeMap, Occupied, Vacant};
 
@@ -1562,7 +1560,7 @@ mod test {
         let mut map: BTreeMap<int, int> = xs.iter().map(|&x| x).collect();
 
         // Existing key (insert)
-        match map.entry(&1) {
+        match map.entry(1) {
             Vacant(_) => unreachable!(),
             Occupied(mut view) => {
                 assert_eq!(view.get(), &10);
@@ -1574,7 +1572,7 @@ mod test {
 
 
         // Existing key (update)
-        match map.entry(&2) {
+        match map.entry(2) {
             Vacant(_) => unreachable!(),
             Occupied(mut view) => {
                 let v = view.get_mut();
@@ -1585,7 +1583,7 @@ mod test {
         assert_eq!(map.len(), 6);
 
         // Existing key (take)
-        match map.entry(&3) {
+        match map.entry(3) {
             Vacant(_) => unreachable!(),
             Occupied(view) => {
                 assert_eq!(view.remove(), 30);
@@ -1596,7 +1594,7 @@ mod test {
 
 
         // Inexistent key (insert)
-        match map.entry(&10) {
+        match map.entry(10) {
             Occupied(_) => unreachable!(),
             Vacant(view) => {
                 assert_eq!(*view.insert(1000), 1000);

src/librustc/lint/builtin.rs

@@ -1328,7 +1328,7 @@ impl UnusedMut {
                 let ident = path1.node;
                 if let ast::BindByValue(ast::MutMutable) = mode {
                     if !token::get_ident(ident).get().starts_with("_") {
-                        match mutables.entry(&ident.name.uint()) {
+                        match mutables.entry(ident.name.uint()) {
                             Vacant(entry) => { entry.insert(vec![id]); },
                             Occupied(mut entry) => { entry.get_mut().push(id); },
                         }

src/librustc/metadata/loader.rs

@@ -400,7 +400,7 @@ impl<'a> Context<'a> {
             info!("lib candidate: {}", path.display());
 
             let hash_str = hash.to_string();
-            let slot = candidates.entry(&hash_str).get().unwrap_or_else(
+            let slot = candidates.entry(hash_str).get().unwrap_or_else(
                 |vacant_entry| vacant_entry.insert((HashSet::new(), HashSet::new())));
             let (ref mut rlibs, ref mut dylibs) = *slot;
             if rlib {

src/librustc/middle/const_eval.rs

@@ -311,7 +311,7 @@ pub fn const_expr_to_pat(tcx: &ty::ctxt, expr: &Expr) -> P<ast::Pat> {
 
         ast::ExprCall(ref callee, ref args) => {
             let def = tcx.def_map.borrow()[callee.id].clone();
-            if let Vacant(entry) = tcx.def_map.borrow_mut().entry(&expr.id) {
+            if let Vacant(entry) = tcx.def_map.borrow_mut().entry(expr.id) {
                entry.insert(def);
             }
             let path = match def {

src/librustc/middle/infer/freshen.rs

@@ -66,7 +66,7 @@ impl<'a, 'tcx> TypeFreshener<'a, 'tcx> {
             None => { }
         }
 
-        match self.freshen_map.entry(&key) {
+        match self.freshen_map.entry(key) {
             Entry::Occupied(entry) => *entry.get(),
             Entry::Vacant(entry) => {
                 let index = self.freshen_count;

src/librustc/middle/infer/region_inference/graphviz.rs

@@ -137,7 +137,7 @@ impl<'a, 'tcx> ConstraintGraph<'a, 'tcx> {
         let mut node_ids = FnvHashMap::new();
         {
             let mut add_node = |&mut : node| {
-                if let Vacant(e) = node_ids.entry(&node) {
+                if let Vacant(e) = node_ids.entry(node) {
                     e.insert(i);
                     i += 1;
                 }

src/librustc/middle/traits/fulfill.rs

@@ -437,11 +437,9 @@ fn register_region_obligation<'tcx>(tcx: &ty::ctxt<'tcx>,
     debug!("register_region_obligation({})",
            region_obligation.repr(tcx));
 
-    let body_id = region_obligation.cause.body_id;
-    match region_obligations.entry(&body_id) {
+    match region_obligations.entry(region_obligation.cause.body_id) {
         Vacant(entry) => { entry.insert(vec![region_obligation]); },
         Occupied(mut entry) => { entry.get_mut().push(region_obligation); },
     }
 
 }
-

src/librustc/middle/ty.rs

@@ -5616,7 +5616,7 @@ pub fn lookup_field_type<'tcx>(tcx: &ctxt<'tcx>,
         node_id_to_type(tcx, id.node)
     } else {
         let mut tcache = tcx.tcache.borrow_mut();
-        let pty = tcache.entry(&id).get().unwrap_or_else(
+        let pty = tcache.entry(id).get().unwrap_or_else(
             |vacant_entry| vacant_entry.insert(csearch::get_field_type(tcx, struct_id, id)));
         pty.ty
     };
@@ -6755,7 +6755,7 @@ pub fn replace_late_bound_regions<'tcx, T, F>(
         debug!("region={}", region.repr(tcx));
         match region {
             ty::ReLateBound(debruijn, br) if debruijn.depth == current_depth => {
-                * map.entry(&br).get().unwrap_or_else(
+                * map.entry(br).get().unwrap_or_else(
                       |vacant_entry| vacant_entry.insert(mapf(br, debruijn)))
             }
             _ => {

src/librustc/session/config.rs

@@ -1115,7 +1115,7 @@ pub fn build_session_options(matches: &getopts::Matches) -> Options {
             None => early_error("--extern value must be of the format `foo=bar`"),
         };
 
-        match externs.entry(&name.to_string()) {
+        match externs.entry(name.to_string()) {
             Vacant(entry) => { entry.insert(vec![location.to_string()]); },
             Occupied(mut entry) => { entry.get_mut().push(location.to_string()); },
         }

src/librustc_resolve/lib.rs

@@ -1688,7 +1688,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         let is_public = import_directive.is_public;
 
         let mut import_resolutions = module_.import_resolutions.borrow_mut();
-        let dest_import_resolution = import_resolutions.entry(&name).get().unwrap_or_else(
+        let dest_import_resolution = import_resolutions.entry(name).get().unwrap_or_else(
             |vacant_entry| {
                 // Create a new import resolution from this child.
                 vacant_entry.insert(ImportResolution::new(id, is_public))
@@ -2626,14 +2626,14 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                             def = DefUpvar(node_id, function_id, last_proc_body_id);
 
                             let mut seen = self.freevars_seen.borrow_mut();
-                            let seen = match seen.entry(&function_id) {
+                            let seen = match seen.entry(function_id) {
                                 Occupied(v) => v.into_mut(),
                                 Vacant(v) => v.insert(NodeSet::new()),
                             };
                             if seen.contains(&node_id) {
                                 continue;
                             }
-                            match self.freevars.borrow_mut().entry(&function_id) {
+                            match self.freevars.borrow_mut().entry(function_id) {
                                 Occupied(v) => v.into_mut(),
                                 Vacant(v) => v.insert(vec![]),
                             }.push(Freevar { def: prev_def, span: span });
@@ -4710,7 +4710,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                 "Import should only be used for `use` directives");
         self.last_private.insert(node_id, lp);
 
-        match self.def_map.borrow_mut().entry(&node_id) {
+        match self.def_map.borrow_mut().entry(node_id) {
             // Resolve appears to "resolve" the same ID multiple
             // times, so here is a sanity check it at least comes to
             // the same conclusion! - nmatsakis