From 0fb37fc67d0d0278022f355bed2aac0c2b772835 Mon Sep 17 00:00:00 2001 From: Jeroen Bollen Date: Sat, 11 Nov 2017 16:21:49 +0100 Subject: [PATCH] Improvided map_entry_replace examples The current examples should be more realistic. --- src/libstd/collections/hash/map.rs | 34 +++++++++++++++++++----------- 1 file changed, 22 insertions(+), 12 deletions(-) diff --git a/src/libstd/collections/hash/map.rs b/src/libstd/collections/hash/map.rs index a7b02fb2b76..7a79a472d58 100644 --- a/src/libstd/collections/hash/map.rs +++ b/src/libstd/collections/hash/map.rs @@ -2247,17 +2247,18 @@ fn take_key(&mut self) -> Option { /// ``` /// #![feature(map_entry_replace)] /// use std::collections::hash_map::{Entry, HashMap}; + /// use std::rc::Rc; /// - /// let mut map: HashMap = HashMap::new(); - /// map.insert("poneyland".to_string(), 15); + /// let mut map: HashMap, u32> = HashMap::new(); + /// map.insert(Rc::new("Stringthing".to_string()), 15); /// - /// if let Entry::Occupied(entry) = map.entry("poneyland".to_string()) { - /// let (old_key, old_value): (String, u32) = entry.replace_entry(16); - /// assert_eq!(old_key, "poneyland"); - /// assert_eq!(old_value, 15); + /// let my_key = Rc::new("Stringthing".to_string()); + /// + /// if let Entry::Occupied(entry) = map.entry(my_key) { + /// // Also replace the key with a handle to our other key. + /// let (old_key, old_value): (Rc, u32) = entry.replace_entry(16); /// } /// - /// assert_eq!(map.get("poneyland"), Some(&16)); /// ``` #[unstable(feature = "map_entry_replace", issue = "44286")] pub fn replace_entry(mut self, value: V) -> (K, V) { @@ -2276,13 +2277,22 @@ pub fn replace_entry(mut self, value: V) -> (K, V) { /// ``` /// #![feature(map_entry_replace)] /// use std::collections::hash_map::{Entry, HashMap}; + /// use std::rc::Rc; + /// + /// let mut map: HashMap, u32> = HashMap::new(); + /// let mut known_strings: Vec> = Vec::new(); + /// + /// // Initialise known strings, run program, etc. /// - /// let mut map: HashMap = HashMap::new(); - /// map.insert("poneyland".to_string(), 15); + /// reclaim_memory(&mut map, &known_strings); /// - /// if let Entry::Occupied(entry) = map.entry("poneyland".to_string()) { - /// let old_key = entry.replace_key(); - /// assert_eq!(old_key, "poneyland"); + /// fn reclaim_memory(map: &mut HashMap, u32>, known_strings: &[Rc] ) { + /// for s in known_strings { + /// if let Entry::Occupied(entry) = map.entry(s.clone()) { + /// // Replaces the entry's key with our version of it in `known_strings`. + /// entry.replace_key(); + /// } + /// } /// } /// ``` #[unstable(feature = "map_entry_replace", issue = "44286")] -- 2.44.0