GitLab

General: Make use of [[maybe_unused]] 

IWindow: Use std::array where applicable

System: Make enum functions noexcept

Avoids the need to have a separate ifdef path to silence an unused
variable warning.

Replaces uses of (void)variable with the attribute introduced in C++17.

Allows for more flexible copying/manipulation within using code. While
we're at it, we can make the interface of SWindowRect and SScrollData
constexpr, given they only manipulate primitives.

This is just a negation, so we can do this to place the logic in one
spot.

Allows them to be used within noexcept contexts