implement unwrap_type from Adapt (#377)

Author: vchuravy

ext/OffsetArraysAdaptExt.jl

@@ -11,6 +11,7 @@ Adapt.adapt_structure(to, O::OffsetArray) = OffsetArrays.parent_call(x -> Adapt.
 @static if isdefined(Adapt, :parent_type)
     # To support Adapt 3.0 which doesn't have parent_type defined
     Adapt.parent_type(::Type{OffsetArray{T,N,AA}}) where {T,N,AA} = AA
+    Adapt.unwrap_type(W::Type{<:OffsetArray}) = unwrap_type(parent_type(W))
 end
 
 end

test/runtests.jl

@@ -2507,8 +2507,12 @@ end
     @test parent(s_arr) isa SArray
     @test arr == adapt(Array, s_arr)
 
+    arr2 = OffsetArray(view(rand(5, 5), 2:4, 2:4), -1:1, -1:1)
+
     if isdefined(Adapt, :parent_type)
         @test Adapt.parent_type(typeof(arr)) == typeof(arr.parent)
+        @test Adapt.unwrap_type(typeof(arr)) == typeof(arr.parent)
+        @test Adapt.unwrap_type(typeof(arr2)) == typeof(arr.parent)
     end
 end