Ensure blocktype is correctly inferred for CuArray

Author: lkdvos

src/tensors/abstracttensor.jl

@@ -313,8 +313,6 @@ end
 #------------------------------------------------------------
 InnerProductStyle(t::AbstractTensorMap) = InnerProductStyle(typeof(t))
 
-blocktype(t::AbstractTensorMap) = blocktype(typeof(t))
-
 numout(t::AbstractTensorMap) = numout(typeof(t))
 numin(t::AbstractTensorMap) = numin(typeof(t))
 numind(t::AbstractTensorMap) = numind(typeof(t))
@@ -441,6 +439,7 @@ See also [`blocks`](@ref), [`blocksectors`](@ref), [`blockdim`](@ref) and [`hasb
 
 Return the type of the matrix blocks of a tensor.
 """ blocktype
+blocktype(t::AbstractTensorMap) = blocktype(typeof(t))
 function blocktype(::Type{T}) where {T <: AbstractTensorMap}
     return Core.Compiler.return_type(block, Tuple{T, sectortype(T)})
 end

src/tensors/tensor.jl

@@ -455,9 +455,7 @@ block(t::TensorMap, c::Sector) = blocks(t)[c]
 
 blocks(t::TensorMap) = BlockIterator(t, fusionblockstructure(t).blockstructure)
 
-function blocktype(::Type{TT}) where {TT <: TensorMap}
-    A = storagetype(TT)
-    T = eltype(A)
+function blocktype(::Type{TensorMap{T, S, N₁, N₂, A}}) where {T, S, N₁, N₂, A <: Vector{T}}
     return Base.ReshapedArray{T, 2, SubArray{T, 1, A, Tuple{UnitRange{Int}}, true}, Tuple{}}
 end