GitLab

Refactored the operator >> and Node::Read default functions, as well as the conversion functions, to more easily read new types as keys (this uncovered an error, in example 2.11 of the spec)

Added templated casting to nodes, as well as operator == and != (for quick checks, especially to help in testing). Implemented size() on a map node to return the number of key/value pairs (as in std::map)

Refactored simple keys so that validating doesn't require popping indents, and so popping indents (and adding the end map) is independent of when we validate the simple key

Fixed bug in anchors with no content. This involved refactoring the 'implicit sequence' concept (where a map and a sequence start on the same indent, but we read the sequence as more indented since the '-' is visually an indent).

Converted indexing to std::size_t, and fixed the Node templated overloads to properly index any index type (determining what is an index type is a bit of a hack - it should be is_convertible<T, std::size_t> (I think), but I just explicitly wrote down a list)

Added emitting for a YAML::Node (instead of the ad-hoc std::ostream overload) so it'll actually emit valid YAML always

It's better organized now, I think - nodes only offer a single main way of getting the fundamental scalar (as a string), and now we can specialize a single template to read specific types.