In 0.4.3, I have defined the following immutable, with a conversion rule to
permit change the type of the wrapped tuple:
immutable Foo{N,T}
co::NTuple{N,T}
end
convert{N,T}(::Type{Foo{N,T}}, input::Foo{N}) = Foo( ([T(input.co[i]) for i
in input.co]...) )
Bar = Foo((1.,2.)) # Returns Foo{2, Float64}((1.0,2.0))
I can explicitly call the convert function:
convert(Foo{2,Float32}, Bar) Returns Foo{2,Float32}((1.0f0, 2.0f0))
I expected that calling the constructor with the desired parameters would
achieve the same, but in fact I receive an error:
Foo{2,Float32}(Bar) # ERROR: MethodError: `convert` has no method matching
convert(::Type{Tuple{Float32,Float32}}, ::Foo{2,Float64})
I do not understand why Julia is dispatching to convert with an argument of
::Type{Tuple{Float32,Float32}}, instead of ::Type{Foo{2,Float32}}, can
someone shed some light on what's going on?
Regards,
Sam.
