BLI: simplify removing elements from containers with predicate

Previously removing elements based on a predicate was a bit cumbersome,
especially for hash tables. Now there is a new `remove_if` method in some
data structures which is similar to `std::erase_if`. We could consider adding
`blender::erase_if` in the future to more closely mimic the standard library,
but for now this is using the api design of the surrounding code is used.

1 files changed, 19 insertions, 0 deletions

diff --git a/source/blender/blenlib/BLI_map.hh b/source/blender/blenlib/BLI_map.hh
index 4322e3c0f2d..d5bc53c4d6c 100644
--- a/source/blender/blenlib/BLI_map.hh
+++ b/source/blender/blenlib/BLI_map.hh
@@ -887,6 +887,25 @@ class Map {
   }
 
   /**
+   * Remove all key-value-pairs for that the given predicate is true.
+   *
+   * This is similar to std::erase_if.
+   */
+  template<typename Predicate> void remove_if(Predicate &&predicate)
+  {
+    for (Slot &slot : slots_) {
+      if (slot.is_occupied()) {
+        const Key &key = *slot.key();
+        Value &value = *slot.value();
+        if (predicate(MutableItem{key, value})) {
+          slot.remove();
+          removed_slots_++;
+        }
+      }
+    }
+  }
+
+  /**
    * Print common statistics like size and collision count. This is useful for debugging purposes.
    */
   void print_stats(StringRef name = "") const