Hi,
Why do i need to specify all the parameters in the signature of methods
that take `::Type` arguments?
Demo:
# define some parametric type
julia> immutable foo{T, N, P, S}
end
# this will not work, but it seems natural to omit trailing unused
parameters
julia> bar{T}(::Type{foo{T}}) = T
bar (generic function with 1 method)
# yes, it does not work
julia> bar(foo{1, 2, 3, 4})
ERROR: MethodError: `bar` has no method matching bar(::Type{foo{1,2,3,4}})
# this will do the job,
julia> bar2{T, N, P, S}(::Type{foo{T, N, P, S}}) = T
bar2 (generic function with 1 method)
# yep
julia> bar2(foo{1, 2, 3, 4})
1
In methods that take instances of a type it is usually not necessary to
specify trailing unused parameter, meaning that, for instance
baz{T}(f::foo{T}) = one(T)
will work for any values of `N`, `P` and `S`.
Thanks!
P.S. This is on 0.4
