GitLab

Changing rule about pascal case public fields. Might reconsider. I'm used to all fields, regardless of accessor, being camel case in order to distinguish them from properties.

Adding test directories. Adding NestedIDictionaryBase to abstract away some shared code for the IDictionary interface would would lead to a lot of duplicated tests among classes that implement it.

Adding new add methods to MultiMap that conditionally add a new key or just add values to an existing key. Also modifying MultiMap to use the new ValueSets pattern.

Adding ValueSets and IValueSets to resolve an outstanding design problem in the entire code base. C# cannot do casts between nested interfaces unless the type is covariant, which means a lot of the code based around casting nested collection interfaces can't work. ValueSets can solve this problem, at least for MultiMap, by acting as an adapter class for the ValueCollection. More classes of this type will probably need to be added.

Modifying MultiMap's AddKey method to throw ArgumentException when the comparer of the passed HashSet is different from the value comparer of the MultiMap. Allowing MultiMap to have HashSets with different comparers could lead to unexpected behaviour.

Added default EqualityComparer assignments to the constructor for comparerValue instead of letting it be null. Behaviour consistent with the core API is to return EqualityComparer<T>.default.