Structs with nested parametric types

General Usage
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1

I’m trying to create a struct with parametric types. I want the struct to have a field of type Array{U{F}}, where U<:Unitful.Length, F<:AbstractFloat. Is there any way to have nested parametric types for structs in Julia?

# Struct definition attempt
using Unitful
julia> s = struct{U<:Unitful.Length, F<:AbstractFloat}
           v::Array{U{F}}
       end

ERROR: syntax: invalid type signature around REPL[22]:1
s = struct
2

Struct definitions don’t use assignment; you haven’t given your struct a name; You’ll have to specify the type parameters of Unitful.Length as well, as UnionAlls are not allowed in a type specification:

julia> struct STRUCT_NAME{F <: AbstractFloat, U <: Unitful.Length{F}}
          v::Vector{U} # only one dimension or more needed?
       end
3 Likes
3

Yup this worked, when copying over the code I had accidentally left out the STRUCT_NAME. The line U <: Unitful.Length{F} was exactly what I was looking for. Thanks!