Dispatch on specific Unitful unit

[Nathan_Boyer]

Saving this here for myself:

Julia's type system : what am I missing?

Adding to @Daniel_Berge 's answer, you can easily dispatch on more specific aliases: const Len{T} = Quantity{T,u"𝐋"} const Met{T} = Quantity{T,u"𝐋",typeof(m)} const Deg{T} = Quantity{T,NoDims,typeof(°)} const Rad{T} = Quantity{T,NoDims,typeof(rad)} You don’t need to construct concrete Unitful.jl types for dispatch. And you can let Julia figure out the exact type in a field using a type parameter: struct Foo{L<:Met} len::L end