Changed default hasher for std::collections::HashSet on fnv::FnvHasher and made some functions generic over std::hash::BuildHashser to accept HashSets with any kind of hashers

Author: Object905

src/graph/algo.rs

@@ -191,8 +191,8 @@ fn cropped_area_of_widget_maybe_within_depth(graph: &Graph,
 /// FIXME: This currently uses call stack recursion to do a depth-first search through all
 /// depth_children for the total bounding box. This should use a proper `Dfs` type with it's own
 /// stack for safer traversal that won't blow the stack on hugely deep GUIs.
-pub fn kids_bounding_box(graph: &Graph,
-                         prev_updated: &std::collections::HashSet<widget::Id>,
+pub fn kids_bounding_box<T: std::hash::BuildHasher>(graph: &Graph,
+                         prev_updated: &std::collections::HashSet<widget::Id, T>,
                          idx: widget::Id) -> Option<Rect>
 {
     // When traversing the `depth_kids`, we only want to visit those who:

src/graph/depth_order.rs

@@ -49,10 +49,10 @@ impl DepthOrder {
     ///
     /// The `visit_by_depth` algorithm should not be recursive and instead use either looping,
     /// walking or iteration.
-    pub fn update(&mut self,
+    pub fn update<T: std::hash::BuildHasher>(&mut self,
                   graph: &Graph,
                   root: widget::Id,
-                  updated_widgets: &std::collections::HashSet<widget::Id>)
+                  updated_widgets: &std::collections::HashSet<widget::Id, T>)
     {
         let DepthOrder { ref mut indices, ref mut floating } = *self;
 
@@ -88,9 +88,9 @@ impl DepthOrder {
 
 
 /// Recursive function for visiting all nodes within the dag.
-fn visit_by_depth(graph: &Graph,
+fn visit_by_depth<T: std::hash::BuildHasher>(graph: &Graph,
                   idx: widget::Id,
-                  updated_widgets: &std::collections::HashSet<widget::Id>,
+                  updated_widgets: &std::collections::HashSet<widget::Id, T>,
                   depth_order: &mut Vec<widget::Id>,
                   floating_deque: &mut Vec<widget::Id>)
 {

src/ui.rs

@@ -5,6 +5,7 @@ use input;
 use position::{self, Align, Direction, Dimensions, Padding, Point, Position, Range, Rect, Scalar};
 use render;
 use std;
+use fnv;
 use text;
 use theme::Theme;
 use utils;
@@ -67,12 +68,12 @@ pub struct Ui {
     /// The order in which widgets from the `widget_graph` are drawn.
     depth_order: graph::DepthOrder,
     /// The set of widgets that have been updated since the beginning of the `set_widgets` stage.
-    updated_widgets: std::collections::HashSet<widget::Id>,
+    updated_widgets: fnv::FnvHashSet<widget::Id>,
     /// The `updated_widgets` for the previous `set_widgets` stage.
     ///
     /// We use this to compare against the newly generated `updated_widgets` to see whether or not
     /// we require re-drawing.
-    prev_updated_widgets: std::collections::HashSet<widget::Id>,
+    prev_updated_widgets: fnv::FnvHashSet<widget::Id>,
     /// Scroll events that have been emitted during a call to `Ui::set_widgets`. These are usually
     /// emitted by some widget like the `Scrollbar`.
     ///
@@ -172,10 +173,11 @@ impl Ui {
             maybe_widgets_capacity.map_or_else(
                 || (Graph::new(),
                    graph::DepthOrder::new(),
-                   std::collections::HashSet::new()),
+                   fnv::FnvHashSet::default()),
                 |n| (Graph::with_node_capacity(n),
                      graph::DepthOrder::with_node_capacity(n),
-                     std::collections::HashSet::with_capacity(n)));
+                     std::collections::HashSet::with_capacity_and_hasher(n,
+                        fnv::FnvBuildHasher::default())));
 
         let window = widget_graph.add_placeholder();
         let prev_updated_widgets = updated_widgets.clone();
@@ -270,15 +272,15 @@ impl Ui {
     ///
     /// This set indicates which widgets have been instantiated since the beginning of the most
     /// recent `Ui::set_widgets` call.
-    pub fn updated_widgets(&self) -> &std::collections::HashSet<widget::Id> {
+    pub fn updated_widgets(&self) -> &fnv::FnvHashSet<widget::Id> {
         &self.updated_widgets
     }
 
     /// Borrow the **Ui**'s set of updated widgets.
     ///
     /// This set indicates which widgets have were instantiated during the previous call to
     /// `Ui::set_widgets`.
-    pub fn prev_updated_widgets(&self) -> &std::collections::HashSet<widget::Id> {
+    pub fn prev_updated_widgets(&self) -> &fnv::FnvHashSet<widget::Id> {
         &self.prev_updated_widgets
     }
 

src/widget/list_select.rs

@@ -120,15 +120,15 @@ pub struct Multiple;
 
 /// Represents some change in item selection for a `ListSelect` in `Multiple` mode.
 #[derive(Clone, Debug)]
-pub enum Selection {
+pub enum Selection<H: std::hash::BuildHasher = std::collections::hash_map::RandomState> {
     /// Items which have been added to the selection.
-    Add(std::collections::HashSet<usize>),
+    Add(std::collections::HashSet<usize, H>),
     /// Items which have been removed from the selection.
-    Remove(std::collections::HashSet<usize>),
+    Remove(std::collections::HashSet<usize, H>),
 }
 
 
-impl Selection {
+impl<H: std::hash::BuildHasher> Selection<H> {
 
     /// Update the given slice of `bool`s with this `Selection`.
     ///
@@ -151,7 +151,9 @@ impl Selection {
     }
 
     /// Update the given set of selected indices with this `Selection`.
-    pub fn update_index_set(&self, set: &mut std::collections::HashSet<usize>) {
+    pub fn update_index_set<T>(&self, set: &mut std::collections::HashSet<usize, T>)
+        where T: std::hash::BuildHasher
+    {
         match *self {
             Selection::Add(ref indices) =>
                 for &i in indices {