Adapt for BraidingTensor (#374)

* implement adapt for BraidingTensor

* add tests

Author: lkdvos

ext/TensorKitAdaptExt.jl

@@ -15,5 +15,8 @@ function Adapt.adapt_structure(to, x::DiagonalTensorMap)
     data′ = adapt(to, x.data)
     return DiagonalTensorMap(data′, x.domain)
 end
+function Adapt.adapt_structure(::Type{TorA}, x::BraidingTensor) where {TorA <: Union{Number, DenseArray{<:Number}}}
+    return BraidingTensor{scalartype(TorA)}(space(x), x.adjoint)
+end
 
 end

test/tensors/planar.jl

@@ -1,4 +1,5 @@
 using Test, TestExtras
+using Adapt
 using TensorKit
 using TensorKit: PlanarTrivial, ℙ
 using TensorKit: planaradd!, planartrace!, planarcontract!
@@ -19,6 +20,9 @@ using .TestSetup
         t2 = @constinferred BraidingTensor{ComplexF64}(W)
         @test scalartype(t2) == ComplexF64
         @test storagetype(t2) == Vector{ComplexF64}
+        t3 = @testinferred adapt(storagetype(t2), t1)
+        @test storagetype(t3) == storagetype(t2)
+        @test t3 == t2
 
         W2 = reverse(codomain(W)) ← domain(W)
         @test_throws SpaceMismatch BraidingTensor(W2)