change PermutedDimsArray to a type (#562)

Author: mcabbott

Project.toml

@@ -1,6 +1,6 @@
 name = "ChainRules"
 uuid = "082447d4-558c-5d27-93f4-14fc19e9eca2"
-version = "1.18.0"
+version = "1.18.1"
 
 [deps]
 ChainRulesCore = "d360d2e6-b24c-11e9-a2a3-2a2ae2dbcce4"

src/rulesets/Base/array.jl

@@ -81,7 +81,7 @@ function rrule(::typeof(permutedims), x::AbstractArray, perm)
     return permutedims(x, perm), permutedims_back_2
 end
 
-function rrule(::typeof(PermutedDimsArray), x::AbstractArray, perm)
+function rrule(::Type{<:PermutedDimsArray}, x::AbstractArray, perm)
     pr = ProjectTo(x)
     permutedims_back_3(dy) = (NoTangent(), pr(permutedims(unthunk(dy), invperm(perm))), NoTangent())
     return PermutedDimsArray(x, perm), permutedims_back_3