dagger(operator)^2 does not work

[Krastanov]

julia> function gen()
           b_fock = FockBasis(10)
           a = destroy(b_fock)
           return dagger(a)^2
       end
gen (generic function with 1 method)

julia> gen()
ERROR: MethodError: Cannot `convert` an object of type 
  Operator{FockBasis{Int64{}},FockBasis{Int64{}},LinearAlgebra.Adjoint{ComplexF64, SparseArrays.SparseMatrixCSC{ComplexF64, Int64}}} to an object of type 
  Operator{FockBasis{Int64{}},FockBasis{Int64{}},SparseArrays.SparseMatrixCSC{ComplexF64, Int64}}

[Krastanov]

julia> a = destroy(FockBasis(5));

julia> Base.power_by_squaring(a', 2)
ERROR: MethodError: Cannot `convert` an object of type 
  Operator{FockBasis{Int64{}},FockBasis{Int64{}},LinearAlgebra.Adjoint{ComplexF64, SparseArrays.SparseMatrixCSC{ComplexF64, Int64}}} to an object of type 
  Operator{FockBasis{Int64{}},FockBasis{Int64{}},SparseArrays.SparseMatrixCSC{ComplexF64, Int64}}

Closest candidates are:
  convert(::Type{T}, ::T) where T
   @ Base Base.jl:64
  Operator{BL, BR, T}(::BL, ::BR, ::T) where {BL, BR, T}
   @ QuantumOpticsBase ~/Documents/ScratchSpace/quantumjulia/QuantumOpticsBase.jl/src/operators_dense.jl:15

Stacktrace:
 [1] to_power_type(x::Operator{FockBasis{Int64}, FockBasis{Int64}, LinearAlgebra.Adjoint{ComplexF64, SparseArrays.SparseMatrixCSC{ComplexF64, Int64}}})
   @ Base ./intfuncs.jl:248
 [2] power_by_squaring(x_::Operator{FockBasis{Int64}, FockBasis{Int64}, LinearAlgebra.Adjoint{ComplexF64, SparseArrays.SparseMatrixCSC{ComplexF64, Int64}}}, p::Int64)
   @ Base ./intfuncs.jl:263
 [3] top-level scope
   @ REPL[37]:1

julia> Base.to_power_type(a')
ERROR: MethodError: Cannot `convert` an object of type 
  Operator{FockBasis{Int64{}},FockBasis{Int64{}},LinearAlgebra.Adjoint{ComplexF64, SparseArrays.SparseMatrixCSC{ComplexF64, Int64}}} to an object of type 
  Operator{FockBasis{Int64{}},FockBasis{Int64{}},SparseArrays.SparseMatrixCSC{ComplexF64, Int64}}

Closest candidates are:
  convert(::Type{T}, ::T) where T
   @ Base Base.jl:64
  Operator{BL, BR, T}(::BL, ::BR, ::T) where {BL, BR, T}
   @ QuantumOpticsBase ~/Documents/ScratchSpace/quantumjulia/QuantumOpticsBase.jl/src/operators_dense.jl:15

Stacktrace:
 [1] to_power_type(x::Operator{FockBasis{Int64}, FockBasis{Int64}, LinearAlgebra.Adjoint{ComplexF64, SparseArrays.SparseMatrixCSC{ComplexF64, Int64}}})
   @ Base ./intfuncs.jl:248
 [2] top-level scope
   @ REPL[38]:1

[Krastanov]

Here is the underlying error:

julia> a = destroy(FockBasis(5));

julia> convert(Base._return_type(*, Tuple{typeof(a.data'), typeof(a.data')}), a.data')
6×6 SparseArrays.SparseMatrixCSC{ComplexF64, Int64} with 5 stored entries:
     ⋅              ⋅              ⋅          ⋅              ⋅          ⋅    
 1.0-0.0im          ⋅              ⋅          ⋅              ⋅          ⋅    
     ⋅      1.41421-0.0im          ⋅          ⋅              ⋅          ⋅    
     ⋅              ⋅      1.73205-0.0im      ⋅              ⋅          ⋅    
     ⋅              ⋅              ⋅      2.0-0.0im          ⋅          ⋅    
     ⋅              ⋅              ⋅          ⋅      2.23607-0.0im      ⋅    

julia> convert(Base._return_type(*, Tuple{typeof(a'), typeof(a')}), a')
ERROR: MethodError: Cannot `convert` an object of type 
  Operator{FockBasis{Int64{}},FockBasis{Int64{}},LinearAlgebra.Adjoint{ComplexF64, SparseArrays.SparseMatrixCSC{ComplexF64, Int64}}} to an object of type 
  Operator{FockBasis{Int64{}},FockBasis{Int64{}},SparseArrays.SparseMatrixCSC{ComplexF64, Int64}}