Retrieving multiple (mutable) components for an entity in 1 go without a lambda

[BasBuur]

Describe the problem you are trying to solve.
Entt allows retrieving n components in 1 go with the following syntax:

auto & [pos, vel] = registry.get<Position, Velocity>(entity);

This is a really nice feature and it would be great if it could be added to flecs. I know flecs allows retrieving multiple components with a lambda but I prefer the components in my local scope without a lambda.

Bonus points if we could get a mutable version as well. For example entity.get_all<Position, Velocity>() and entity.get_all_mut<Position, Velocity>().

[SanderMertens]

I'm planning to migrate the API to C++17 which will enable this API. I'm expecting to begin working on this within a month.