nfield(x::DataType)

[matthieugomez]

I think that nfield(x::DataType) returns a wrong result on the current master version with Julia 0.6.

using NamedTuples
x = @NT(a = 0.0, b = 0.0, c = 0.0)
nfields(NamedTuples._NT_a_b_c)
# returns 2 while I expected 3

The registered version on Metadata with Julia 0.5 returns 3, which is the answer I expected

[shashi]

julia> using NamedTuples

julia> x = @NT(a = 0.0, b = 0.0, c = 0.0)
(a = 0.0, b = 0.0, c = 0.0)

julia> nfields(NamedTuples._NT_a_b_c)
2

# however:
julia> nfields(typeof(x))
3

Not sure if this is a bug. cc @JeffBezanson

[JeffBezanson]

Yes, this is not specific to NamedTuples. Currently it's giving 2 since a UnionAll type has 2 components. I'm not sure what to do in this case, but it should be addressed in base julia.

[matthieugomez]

See discussion in JuliaLang/julia#22350