Avoid extra copy in Vector/CowData push_back/insert

Update push_back/insert methods to move new item into CowData instead of copying

Author: aaronp64

core/templates/cowdata.h

@@ -206,8 +206,8 @@ class CowData {
 
 	_FORCE_INLINE_ void remove_at(Size p_index);
 
-	Error insert(Size p_pos, const T &p_val);
-	Error push_back(const T &p_val);
+	Error insert(Size p_pos, T &&p_val);
+	Error push_back(T &&p_val);
 
 	_FORCE_INLINE_ operator Span<T>() const { return Span<T>(ptr(), size()); }
 	_FORCE_INLINE_ Span<T> span() const { return operator Span<T>(); }
@@ -296,7 +296,7 @@ void CowData<T>::remove_at(Size p_index) {
 }
 
 template <typename T>
-Error CowData<T>::insert(Size p_pos, const T &p_val) {
+Error CowData<T>::insert(Size p_pos, T &&p_val) {
 	const Size new_size = size() + 1;
 	ERR_FAIL_INDEX_V(p_pos, new_size, ERR_INVALID_PARAMETER);
 
@@ -326,13 +326,13 @@ Error CowData<T>::insert(Size p_pos, const T &p_val) {
 	}
 
 	// Create the new element at the given index.
-	memnew_placement(_ptr + p_pos, T(p_val));
+	memnew_placement(_ptr + p_pos, T(std::move(p_val)));
 
 	return OK;
 }
 
 template <typename T>
-Error CowData<T>::push_back(const T &p_val) {
+Error CowData<T>::push_back(T &&p_val) {
 	const Size new_size = size() + 1;
 
 	if (!_ptr) {
@@ -361,7 +361,7 @@ Error CowData<T>::push_back(const T &p_val) {
 	}
 
 	// Create the new element at the given index.
-	memnew_placement(_ptr + new_size - 1, T(p_val));
+	memnew_placement(_ptr + new_size - 1, T(std::move(p_val)));
 
 	return OK;
 }

core/templates/vector.h

@@ -71,8 +71,8 @@ class Vector {
 
 public:
 	// Must take a copy instead of a reference (see GH-31736).
-	_FORCE_INLINE_ bool push_back(T p_elem) { return _cowdata.push_back(p_elem); }
-	_FORCE_INLINE_ bool append(const T &p_elem) { return push_back(p_elem); } //alias
+	_FORCE_INLINE_ bool push_back(T p_elem) { return _cowdata.push_back(std::move(p_elem)); }
+	_FORCE_INLINE_ bool append(T p_elem) { return _cowdata.push_back(std::move(p_elem)); } //alias
 	void fill(T p_elem);
 
 	void remove_at(Size p_index) { _cowdata.remove_at(p_index); }
@@ -133,7 +133,7 @@ class Vector {
 
 	_FORCE_INLINE_ const T &operator[](Size p_index) const { return _cowdata.get(p_index); }
 	// Must take a copy instead of a reference (see GH-31736).
-	Error insert(Size p_pos, T p_val) { return _cowdata.insert(p_pos, p_val); }
+	Error insert(Size p_pos, T p_val) { return _cowdata.insert(p_pos, std::move(p_val)); }
 	Size find(const T &p_val, Size p_from = 0) const {
 		if (p_from < 0) {
 			p_from = size() + p_from;