0000.0001.md

# Add `requires core::utility::UnqualifiedObject<T>` anywhere that we store a `T`

## Explanation

Lots of our types have the same few `static_assert()`s as the first few statements in their bodies:

- Not a reference
- Not `const`
- Not `volatile`

Strictly speaking, the only ones we _need_ from this list are reference and `const`, but `volatile`
completes the picture (and instantiating a template with a `volatile` type is probably a bug
anyway).

These assertions are now encapsulated in the `core::utility::UnqualifiedObject` concept. This
communicates intent more clearly and is also less boilerplate.

## Task

Apply `requires core::utility::UnqualifiedObject<T>` to every type where it makes sense. Note that
it should almost entirely be applied to class templates, not function templates; unless the function
is creating a local variable of type `T`, there's no reason to add more boilerplate in places where
it doesn't matter.