Use std::vector::swap instead of assignment

December 14, 2009 · 1 min read

If your code assigns one std::vector to another and you won’t need the source vector afterwards, use the vector’s swap member function instead. Assignment copies the elements into the destination, which can mean allocating a new buffer. Swap only exchanges the internal buffers of the two vectors, so you save one memory allocation.

void SetPath_Dirty(vec3& path) {
	m_path.swap(path);
}

After the call, path holds whatever m_path held before, so the caller shouldn’t rely on its contents.