Bug 275191 – Make WTF containers std::ranges compatible

• Status: NEW
• Component: Web Template Framework

[Sam Weinig]

Many of the containers defined in WTF are not compatible with std::ranges, mostly due to invalid iterator implementations.

To allow using std::ranges, we should update the implementations to conform to the associated concepts and then statically assert the concepts hold.

The easiest way to test if a container is compatible with std::ranges is to compile the code:

```
static_assert(std::range<ContainerName>);
```

but in general, we should usually be further constraining things with a concept with more requirements. For instance, most of our containers have a known size, so they should at least be "std::sized_range<>".


Similarly, iterators can now be statically asserted as conforming using the iterator concepts: "static_assert(std::forward_iterator<FooIterator>);"

[Radar WebKit Bug Importer]

<rdar://problem/129728373>