C++

25.8    Copy instead of Assignment: Values in Uninitialized Memory Areas

All functions from <algorithm> use assignment with E& operator=(const E&) when moving elements. With move_iterator, you can make an algorithm use the move assignment E& operator=(E&&) instead. But in both cases, an object must already exist at the destination. That means you need to initialize the entire target range with valid objects first. This can be cumbersome and unnecessary as you know that copy will overwrite the entire range anyway.

In the <memory> header, there are a handful of additional algorithms that do not require a valid object at the destination. The objects are then created with the copy constructor E(const E&) in uninitialized memory, not overwritten. ...