From 04105c91ae2e2bbcc5924a03daab9d457f526513 Mon Sep 17 00:00:00 2001
From: Keno Fischer <keno@alumni.harvard.edu>
Date: Tue, 15 Oct 2019 18:37:51 -0400
Subject: [PATCH 1/2] Implement three-argument `similar` methods

Array wrappers such as `OffsetArray` assume that the three argument
version exists for its interior arrays.
---
 src/structarray.jl | 10 +++++++++-
 test/runtests.jl   |  6 ++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/src/structarray.jl b/src/structarray.jl
index f9b43c0a..a93e7bf0 100644
--- a/src/structarray.jl
+++ b/src/structarray.jl
@@ -102,10 +102,18 @@ end
 
 Base.similar(s::StructArray, sz::Base.DimOrInd...) = similar(s, Base.to_shape(sz))
 Base.similar(s::StructArray) = similar(s, Base.to_shape(axes(s)))
-function Base.similar(s::StructArray{T}, sz::Tuple) where {T}
+function Base.similar(s::StructArray{T,N,C}, ::Type{T}, sz::NTuple{N,Int64}) where {T, N, C<:Union{Tuple, NamedTuple}}
     StructArray{T}(map(typ -> similar(typ, sz), fieldarrays(s)))
 end
 
+function Base.similar(s::StructArray{T,N,C}, S::Type, sz::NTuple{N,Int64}) where {T, N, C<:Union{Tuple, NamedTuple}}
+    # If not specified, we don't really know what kind of array to use for each
+    # interior type, so we just pick the first one arbitrarily. If users need
+    # something else, they need to be more specific.
+    f1 = fieldarrays(s)[1]
+    buildfromschema(typ -> similar(f1, typ, sz), S)
+end
+
 """
 `fieldarrays(s::StructArray)`
 
diff --git a/test/runtests.jl b/test/runtests.jl
index f699f8b1..5c74d9fa 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -646,3 +646,9 @@ end
     str = String(take!(io))
     @test str == "StructArray(::Array{Int64,1}, ::Array{Int64,1})"
 end
+
+@testset "OffsetArray zero" begin
+    s = StructArray{ComplexF64}((rand(2), rand(2)))
+    soff = OffsetArray(s, 0:1)
+    @test isa(zero(soff).parent, StructArray)
+end

From a7576f689ee6d8fa37fd502831f21db82f7b5203 Mon Sep 17 00:00:00 2001
From: Pietro Vertechi <pietro.vertechi@protonmail.com>
Date: Fri, 18 Mar 2022 19:43:31 +0100
Subject: [PATCH 2/2] Apply suggestions from code review

Co-authored-by: Lucas C Wilcox <lucas@swirlee.com>
---
 src/structarray.jl | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/structarray.jl b/src/structarray.jl
index a93e7bf0..924937db 100644
--- a/src/structarray.jl
+++ b/src/structarray.jl
@@ -102,16 +102,20 @@ end
 
 Base.similar(s::StructArray, sz::Base.DimOrInd...) = similar(s, Base.to_shape(sz))
 Base.similar(s::StructArray) = similar(s, Base.to_shape(axes(s)))
-function Base.similar(s::StructArray{T,N,C}, ::Type{T}, sz::NTuple{N,Int64}) where {T, N, C<:Union{Tuple, NamedTuple}}
+function Base.similar(s::StructArray{T,N,C}, ::Type{T}, sz::NTuple{M,Int64}) where {T, N, M, C<:Union{Tuple, NamedTuple}}
     StructArray{T}(map(typ -> similar(typ, sz), fieldarrays(s)))
 end
 
-function Base.similar(s::StructArray{T,N,C}, S::Type, sz::NTuple{N,Int64}) where {T, N, C<:Union{Tuple, NamedTuple}}
+function Base.similar(s::StructArray{T,N,C}, S::Type, sz::NTuple{M,Int64}) where {T, N, M, C<:Union{Tuple, NamedTuple}}
     # If not specified, we don't really know what kind of array to use for each
     # interior type, so we just pick the first one arbitrarily. If users need
     # something else, they need to be more specific.
     f1 = fieldarrays(s)[1]
-    buildfromschema(typ -> similar(f1, typ, sz), S)
+    if isstructtype(S)
+        return StructArrays.buildfromschema(typ -> similar(f1, typ, sz), S)
+    else
+        return similar(f1, S, sz)
+    end
 end
 
 """