libcore: Taking pointers from PointerSet

skyjake · Sep 1, 2019 · e47ac72 · e47ac72
1 parent 7728dd1
commit e47ac72
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Showing 3 changed files with 24 additions and 0 deletions.
diff --git a/doomsday/libs/core/include/de/data/pointerset.h b/doomsday/libs/core/include/de/data/pointerset.h
@@ -63,6 +63,7 @@ class DE_PUBLIC PointerSet
     void remove(Pointer ptr);
     bool contains(Pointer ptr) const;
     void clear();
+    Pointer take();
 
     PointerSet &operator = (PointerSet const &other);
     PointerSet &operator = (PointerSet &&moved);
@@ -146,6 +147,9 @@ class PointerSetT : public PointerSet
     inline const_iterator end() const {
         return reinterpret_cast<const_iterator>(PointerSet::end());
     }
+    inline Pointer take() {
+        return reinterpret_cast<Pointer>(PointerSet::take());
+    }
 };
 
 } // namespace de

diff --git a/doomsday/libs/core/src/data/pointerset.cpp b/doomsday/libs/core/src/data/pointerset.cpp
@@ -209,6 +209,22 @@ void PointerSet::clear()
         _range = Rangeui16(_range.end, _range.end);
     }
 }
+
+PointerSet::Pointer PointerSet::take()
+{
+    if (isEmpty()) return nullptr;
+    Pointer ptr = nullptr;
+    // Make room at both ends.
+    if (_size - _range.end < _range.start)
+    {
+        std::swap(ptr, _pointers[--_range.end]);
+    }
+    else
+    {
+        std::swap(ptr, _pointers[_range.start++]);
+    }
+    return ptr;
+}
 
 PointerSet &PointerSet::operator = (PointerSet const &other)
 {

diff --git a/doomsday/tests/test_pointerset/main.cpp b/doomsday/tests/test_pointerset/main.cpp
@@ -100,6 +100,10 @@ int main(int, char **)
         pset.insert(b);
         pset.insert(a);
         printSet(pset);
+
+        cout << "Taking one:" << endl;
+        pset.take();
+        printSet(pset);
 
         cout << "Removing everything:" << endl;
         pset.remove(d);