2012658 - Use move semantic instead of copy when possible

Status: NEW

(Core :: General, task)

Description

[[:sergesanspaille]]

Coverity recently pointed out that performance bug in our code: Bug 2012340.
Basically when a value is copied at some point and not used any further, it's better to move it (and I like to move it!).

Minimal example

void foo(std::vector<int>& out, std::vector<int> in) {
    out = in; // << better to std::move there
}

This is a source of inefficiencies we should be removing.