From ea45e192ceff7f0bfb093140ba56da9f6f326e03 Mon Sep 17 00:00:00 2001
From: Katharine Hyatt <khyatt@flatironinstitute.org>
Date: Wed, 4 Nov 2026 07:29:09 -0500
Subject: [PATCH] Add an adapt method for SectorVector

---
 src/tensors/sectorvector.jl  |  2 ++
 test/amd/tensors.jl          | 17 +++++++++++++++++
 test/cuda/tensors.jl         | 17 +++++++++++++++++
 test/tensors/sectorvector.jl | 14 ++++++++++++++
 4 files changed, 50 insertions(+)

diff --git a/src/tensors/sectorvector.jl b/src/tensors/sectorvector.jl
index 5c11c66e3..2eceaba2d 100644
--- a/src/tensors/sectorvector.jl
+++ b/src/tensors/sectorvector.jl
@@ -41,6 +41,8 @@ Base.similar(v::SectorVector, ::Type{T}, V::ElementarySpace) where {T} = SectorV
 
 Base.copy(v::SectorVector) = SectorVector(copy(v.data), v.structure)
 
+Adapt.adapt_structure(to, v::SectorVector) = SectorVector(Adapt.adapt(to, parent(v)), v.structure)
+
 # AbstractDict interface
 # ----------------------
 Base.keytype(v::SectorVector) = keytype(typeof(v))
diff --git a/test/amd/tensors.jl b/test/amd/tensors.jl
index 9bf1d1997..a8da66b01 100644
--- a/test/amd/tensors.jl
+++ b/test/amd/tensors.jl
@@ -97,6 +97,23 @@ for V in spacelist
                 @test domain(t2) == one(W)
             end
         end
+        @timedtestset "Adapt SectorVector" begin
+            for T in (Float32, ComplexF64)
+                v = TensorKit.SectorVector{T}(undef, V1)
+                rand!(parent(v))
+                v_gpu = @constinferred adapt(ROCArray, v)
+                @test v_gpu isa TensorKit.SectorVector{T, I, <:ROCArray{T}}
+                @test v_gpu.structure == v.structure
+                v_cpu = @constinferred adapt(Array, v_gpu)
+                @test v_cpu isa TensorKit.SectorVector{T, I, Vector{T}}
+                @test parent(v_cpu) == parent(v)
+                t = AMDGPU.randn(T, V1 ⊗ V2 ← V3)
+                s = svd_vals(t)
+                s_cpu = adapt(Array, s)
+                @test parent(s_cpu) == collect(parent(s))
+                @test all(c -> block(s_cpu, c) == collect(block(s, c)), blocksectors(s))
+            end
+        end
         @timedtestset "Tensor Dict conversion" begin
             W = V1 ⊗ V2 ← (V3 ⊗ V4 ⊗ V5)'
             for T in (Int, Float32, ComplexF64)
diff --git a/test/cuda/tensors.jl b/test/cuda/tensors.jl
index 68e3bfa8f..7e66ad762 100644
--- a/test/cuda/tensors.jl
+++ b/test/cuda/tensors.jl
@@ -115,6 +115,23 @@ for V in spacelist
                 @test storagetype(t_cpu) <: Array{T}
             end
         end
+        @timedtestset "Adapt SectorVector" begin
+            for T in (Float32, ComplexF64)
+                v = TensorKit.SectorVector{T}(undef, V1)
+                rand!(parent(v))
+                v_gpu = @constinferred adapt(CuArray, v)
+                @test v_gpu isa TensorKit.SectorVector{T, I, <:CuArray{T}}
+                @test v_gpu.structure == v.structure
+                v_cpu = @constinferred adapt(Array, v_gpu)
+                @test v_cpu isa TensorKit.SectorVector{T, I, Vector{T}}
+                @test parent(v_cpu) == parent(v)
+                t = CUDA.randn(T, V1 ⊗ V2 ← V3)
+                s = svd_vals(t)
+                s_cpu = adapt(Array, s)
+                @test parent(s_cpu) == collect(parent(s))
+                @test all(c -> block(s_cpu, c) == collect(block(s, c)), blocksectors(s))
+            end
+        end
         @timedtestset "Tensor Dict conversion" begin
             W = V1 ⊗ V2 ← (V3 ⊗ V4 ⊗ V5)'
             for T in (Int, Float32, ComplexF64)
diff --git a/test/tensors/sectorvector.jl b/test/tensors/sectorvector.jl
index 22832404c..1ff8e3dbb 100644
--- a/test/tensors/sectorvector.jl
+++ b/test/tensors/sectorvector.jl
@@ -1,6 +1,7 @@
 using Test, TestExtras
 using TensorKit
 using TensorKit: SectorVector, diagonalblockstructure
+using Adapt: adapt
 
 spacelist = (
     (ℂ^4)',
@@ -29,6 +30,19 @@ spacelist = (
             @test length(v3) == reduceddim(V)
         end
 
+        @timedtestset "Adapt ($T)" begin
+            v = SectorVector{T}(undef, V)
+            rand!(parent(v))
+            w = @testinferred adapt(Array, v)
+            @test w isa SectorVector{T, I, Vector{T}}
+            @test parent(w) == parent(v)
+            @test w.structure == v.structure
+            T′ = T <: Complex ? ComplexF64 : Float64
+            w′ = @testinferred adapt(Array{T′}, v)
+            @test w′ isa SectorVector{T′, I, Vector{T′}}
+            @test parent(w′) ≈ parent(v)
+        end
+
         @timedtestset "AbstractVector interface ($T)" begin
             v = SectorVector{T}(undef, V)
             rand!(parent(v))