True if T is an instance of SumType, otherwise false.
This placeholder, for use in self-referential types.
A tagged union that can hold a single value from any of a specified set of types.
Calls a type-appropriate function with the value held in a SumType.
True if handler is a potential match for T, otherwise false.
A sum type for modern D.
SumType is an alternative to std.variant.Algebraic that features: