Add can_setindex methods (#251)

* Add `can_setindex` methods

Author: Tokazama

Project.toml

@@ -1,6 +1,6 @@
 name = "ArrayInterface"
 uuid = "4fba245c-0d91-5ea0-9b3e-6abc04ee57a9"
-version = "5.0.3"
+version = "5.0.4"
 
 [deps]
 Compat = "34da2185-b29b-5c13-b0c7-acf172513d20"

src/ArrayInterface.jl

@@ -13,6 +13,8 @@ import Compat
 using Base: @propagate_inbounds, tail, OneTo, LogicalIndex, Slice, ReinterpretArray,
     ReshapedArray, AbstractCartesianIndex
 
+using Base.Iterators: Pairs
+
 const CanonicalInt = Union{Int,StaticInt}
 canonicalize(x::Integer) = Int(x)
 canonicalize(@nospecialize(x::StaticInt)) = x
@@ -187,6 +189,11 @@ Query whether a type can use `setindex!`.
 can_setindex(x) = can_setindex(typeof(x))
 can_setindex(::Type) = true
 can_setindex(::Type{<:AbstractRange}) = false
+can_setindex(::Type{<:AbstractDict}) = true
+can_setindex(::Type{<:Base.ImmutableDict}) = false
+can_setindex(@nospecialize T::Type{<:Tuple}) = false
+can_setindex(@nospecialize T::Type{<:NamedTuple}) = false
+can_setindex(::Type{<:Pairs{<:Any,<:Any,P}}) where {P} = can_setindex(P)
 
 """
     aos_to_soa(x)

test/runtests.jl

@@ -72,6 +72,10 @@ end
     @test !@inferred(ArrayInterface.can_setindex(1:2))
     @test @inferred(ArrayInterface.can_setindex(Vector{Int}))
     @test !@inferred(ArrayInterface.can_setindex(UnitRange{Int}))
+    @test !@inferred(ArrayInterface.can_setindex(Base.ImmutableDict{Int,Int}))
+    @test !@inferred(ArrayInterface.can_setindex(Tuple{}))
+    @test !@inferred(ArrayInterface.can_setindex(NamedTuple{(),Tuple{}}))
+    @test @inferred(ArrayInterface.can_setindex(Dict{Int,Int}))
 end
 
 @testset "ArrayInterface.isstructured" begin