Resolve the review comments

1. Update Project.toml.
2. test `backend`'s inferability.

Co-Authored-By: Pietro Vertechi <6333339+piever@users.noreply.github.com>

Author: N5N3

Project.toml

@@ -14,7 +14,7 @@ Adapt = "1, 2, 3"
 DataAPI = "1"
 StaticArraysCore = "1.3"
 StaticArrays = "1.5.6"
-GPUArraysCore = "~0.1.2"
+GPUArraysCore = "0.1.2"
 Tables = "1"
 julia = "1.6"
 

src/StructArrays.jl

@@ -32,9 +32,11 @@ Adapt.adapt_structure(to, s::StructArray) = replace_storage(x->Adapt.adapt(to, x
 # for GPU broadcast
 import GPUArraysCore
 function GPUArraysCore.backend(::Type{T}) where {T<:StructArray}
-    backs = map(GPUArraysCore.backend, fieldtypes(array_types(T)))
-    all(Base.Fix2(===, backs[1]), tail(backs)) || error("backend mismatch!")
-    return backs[1]
+    backends = map_params(GPUArraysCore.backend, array_types(T))
+    backend, others = backends[1], tail(backends)
+    isconsistent = mapfoldl(isequal(backend), &, others; init=true)
+    isconsistent || throw(ArgumentError("all component arrays must have the same GPU backend"))
+    return backend
 end
 
 end # module

test/runtests.jl

@@ -1232,6 +1232,8 @@ Base.BroadcastStyle(::Broadcast.ArrayStyle{MyArray2}, S::Broadcast.DefaultArrayS
         bcmul2(a) = 2 .* a
         a = StructArray(randn(ComplexF32, 10, 10))
         sa = jl(a)
+        backend = StructArrays.GPUArraysCore.backend
+        @test @inferred(backend(sa)) === backend(sa.re) === backend(sa.im)
         @test collect(@inferred(bcabs(sa))) == bcabs(a)
         @test @inferred(bcmul2(sa)) isa StructArray
         @test (sa .+= 1) isa StructArray