Maintain mutability of SizedArray under similar_type

Author: Andy Ferris

src/abstractarray.jl

@@ -116,12 +116,12 @@ end
 @pure similar_type{SA<:StaticArray,N}(::Union{SA,Type{SA}}, sizes::Tuple{Vararg{Int,N}}) = SArray{sizes, eltype(SA), N, prod(sizes)}
 
 # Some specializations for the mutable case
-@pure similar_type{MA<:Union{MVector,MMatrix,MArray}}(::Union{MA,Type{MA}}, size::Int) = MVector{size, eltype(MA)}
-@pure similar_type{MA<:Union{MVector,MMatrix,MArray}}(::Union{MA,Type{MA}}, sizes::Tuple{Int}) = MVector{sizes[1], eltype(MA)}
+@pure similar_type{MA<:Union{MVector,MMatrix,MArray,SizedArray}}(::Union{MA,Type{MA}}, size::Int) = MVector{size, eltype(MA)}
+@pure similar_type{MA<:Union{MVector,MMatrix,MArray,SizedArray}}(::Union{MA,Type{MA}}, sizes::Tuple{Int}) = MVector{sizes[1], eltype(MA)}
 
-@pure similar_type{MA<:Union{MVector,MMatrix,MArray}}(::Union{MA,Type{MA}}, sizes::Tuple{Int,Int}) = MMatrix{sizes[1], sizes[2], eltype(MA), sizes[1]*sizes[2]}
+@pure similar_type{MA<:Union{MVector,MMatrix,MArray,SizedArray}}(::Union{MA,Type{MA}}, sizes::Tuple{Int,Int}) = MMatrix{sizes[1], sizes[2], eltype(MA), sizes[1]*sizes[2]}
 
-@pure similar_type{MA<:Union{MVector,MMatrix,MArray},N}(::Union{MA,Type{MA}}, sizes::Tuple{Vararg{Int,N}}) = MArray{sizes, eltype(MA), N, prod(sizes)}
+@pure similar_type{MA<:Union{MVector,MMatrix,MArray,SizedArray},N}(::Union{MA,Type{MA}}, sizes::Tuple{Vararg{Int,N}}) = MArray{sizes, eltype(MA), N, prod(sizes)}
 
 # And also similar() returning mutable StaticArrays
 @inline similar{SV <: StaticVector}(::SV) = MVector{length(SV),eltype(SV)}()