Fixed struct definition

Author: jonniedie

src/componentarray.jl

@@ -31,7 +31,7 @@ julia> collect(x)
    2
 ```
 """
-struct ComponentArray{T,N,A<:AbstractArray{T,N},Axes<:Tuple{Vararg{AbstractAxis}}} <: DenseArray{T,N}
+struct ComponentArray{T,N,A<:AbstractArray{T,N},Axes<:Tuple{Vararg{<:AbstractAxis}}} <: DenseArray{T,N}
     data::A
     axes::Axes
 end

src/if_required/chainrulescore.jl

@@ -1,3 +1,5 @@
+using ChainRulesCore: NO_FIELDS
+
 # ChainRulesCore.frule(Δ, ::typeof(getproperty), x::ComponentArray, s::Symbol) = frule((_, Δ), getproperty, x, Val(s))
 # function ChainRulesCore.frule(Δ, ::typeof(getproperty), x::ComponentArray, ::Val{s}) where s
 #     zero_x = zero(x)
@@ -16,8 +18,11 @@ function ChainRulesCore.rrule(::typeof(getproperty), x::ComponentArray, ::Val{s}
 end
 
 # ChainRulesCore.frule(::typeof(getdata), x::ComponentArray) = getdata(x), Δ->ComponentArray(Δ, getaxes(x))
-ChainRulesCore.rrule(::typeof(getdata), x::ComponentArray) = getdata(x), Δ->ComponentArray(Δ, getaxes(x))
+ChainRulesCore.rrule(::typeof(getdata), x::ComponentArray) = getdata(x), Δ->(NO_FIELDS, ComponentArray(Δ, getaxes(x)))
+
+ChainRulesCore.rrule(::typeof(getaxes), x::ComponentArray) = getaxes(x), Δ->(NO_FIELDS, ComponentArray(getdata(x), Δ))
 
-ChainRulesCore.rrule(::typeof(getaxes), x::ComponentArray) = getaxes(x), Δ->ComponentArray(getdata(x), Δ)
+ChainRulesCore.rrule(::Type{ComponentArray}, data, axes) = ComponentArray(data, axes), Δ->(NO_FIELDS, getdata(Δ), getaxes(Δ))
 
-ChainRulesCore.rrule(::typeof(ComponentArray), data, axes) = ComponentArray(data, axes), Δ->(getdata(Δ), getaxes(Δ))
+ChainRulesCore.rrule(::Type{Axis}, nt) = Axis(nt), Δ->(NO_FIELDS, ComponentArrays.indexmap(Δ))
+ChainRulesCore.rrule(::Type{Axis}; kwargs...) = Axis(; kwargs...), Δ->(NO_FIELDS, (; ComponentArrays.indexmap(Δ)...))