make similar mutable for non bits types (#1196)

* make similar mutable for non bits types

* add quick test

* Update src/abstractarray.jl

Co-authored-by: Mateusz Baran <[email protected]>

---------

Co-authored-by: Mateusz Baran <[email protected]>

Author: adienes

src/abstractarray.jl

@@ -128,8 +128,11 @@ similar(::Type{A},s::Size{S}) where {A<:AbstractArray,S} = similar(A,eltype(A),s
 
 similar(::A,::Type{T},s::Size{S}) where {A<:AbstractArray,T,S} = similar(A,T,s)
 
-# defaults to built-in mutable types
-similar(::Type{A},::Type{T},s::Size{S}) where {A<:AbstractArray,T,S} = mutable_similar_type(T,s,length_val(s))(undef)
+# defaults to built-in mutable types for bits types
+similar(::Type{A}, ::Type{T}, s::Size{S}) where {A<:AbstractArray,T,S} =
+    isbitstype(T) ?
+    mutable_similar_type(T, s, length_val(s))(undef) :
+    sizedarray_similar_type(T, s, length_val(s))(undef)
 
 # both SizedArray and Array return SizedArray
 similar(::Type{SA},::Type{T},s::Size{S}) where {SA<:SizedArray,T,S} = sizedarray_similar_type(T,s,length_val(s))(undef)

test/abstractarray.jl

@@ -59,6 +59,7 @@ using StaticArrays, Test, LinearAlgebra
         sv = @SVector [1,2,3]
         sm = @SMatrix [1 2; 3 4]
         sa = SArray{Tuple{1,1,1},Int,3,1}((1,))
+        sn = @SVector [1, missing]
 
         @test isa(@inferred(similar(sv)), MVector{3,Int})
         @test isa(@inferred(similar(sv, Float64)), MVector{3,Float64})
@@ -69,6 +70,8 @@ using StaticArrays, Test, LinearAlgebra
         @test isa(@inferred(similar(sm, Float64)), MMatrix{2,2,Float64,4})
         @test isa(@inferred(similar(sv, Size(3,3))), MMatrix{3,3,Int,9})
         @test isa(@inferred(similar(sv, Float64, Size(3,3))), MMatrix{3,3,Float64,9})
+        @test isa(@inferred(similar(sn)), SizedVector{2, Union{Missing, Int}})
+        @test isa(@inferred(similar(sn, Float64, Size(3, 3))), MMatrix{3, 3, Float64, 9})
 
         @test isa(@inferred(similar(sa)), MArray{Tuple{1,1,1},Int,3,1})
         @test isa(@inferred(similar(SArray{Tuple{1,1,1},Int,3,1})), MArray{Tuple{1,1,1},Int,3,1})