to_vec errors for StepRanges

[oxinabox]

idk why, i thought this would be caught by our handling of arrays?

julia> v, from_vec = FiniteDifferences.to_vec(1.0:2.0)
([1.0, 0.0, 1.0, 0.0, 2.0, 1.0], FiniteDifferences.var"#structtype_from_vec#29"{StepRangeLen{Float64, Base.TwicePrecision{Float64}, Base.TwicePrecision{Float64}}, FiniteDifferences.var"#Tuple_from_vec#48"{NTuple{4, Int64}, NTuple{4, Int64}, NTuple{4, typeof(identity)}}, Tuple{FiniteDifferences.var"#structtype_from_vec#29"{Base.TwicePrecision{Float64}, FiniteDifferences.var"#Tuple_from_vec#48"{Tuple{Int64, Int64}, Tuple{Int64, Int64}, Tuple{typeof(identity), typeof(identity)}}, Tuple{FiniteDifferences.var"#Real_from_vec#20", FiniteDifferences.var"#Real_from_vec#20"}}, FiniteDifferences.var"#structtype_from_vec#29"{Base.TwicePrecision{Float64}, FiniteDifferences.var"#Tuple_from_vec#48"{Tuple{Int64, Int64}, Tuple{Int64, Int64}, Tuple{typeof(identity), typeof(identity)}}, Tuple{FiniteDifferences.var"#Real_from_vec#20", FiniteDifferences.var"#Real_from_vec#20"}}, FiniteDifferences.var"#Real_from_vec#20", FiniteDifferences.var"#Real_from_vec#20"}}(FiniteDifferences.var"#Tuple_from_vec#48"{NTuple{4, Int64}, NTuple{4, Int64}, NTuple{4, typeof(identity)}}((2, 4, 5, 6), (2, 2, 1, 1), (identity, identity, identity, identity)), (FiniteDifferences.var"#structtype_from_vec#29"{Base.TwicePrecision{Float64}, FiniteDifferences.var"#Tuple_from_vec#48"{Tuple{Int64, Int64}, Tuple{Int64, Int64}, Tuple{typeof(identity), typeof(identity)}}, Tuple{FiniteDifferences.var"#Real_from_vec#20", FiniteDifferences.var"#Real_from_vec#20"}}(FiniteDifferences.var"#Tuple_from_vec#48"{Tuple{Int64, Int64}, Tuple{Int64, Int64}, Tuple{typeof(identity), typeof(identity)}}((1, 2), (1, 1), (identity, identity)), (FiniteDifferences.var"#Real_from_vec#20"(), FiniteDifferences.var"#Real_from_vec#20"())), FiniteDifferences.var"#structtype_from_vec#29"{Base.TwicePrecision{Float64}, FiniteDifferences.var"#Tuple_from_vec#48"{Tuple{Int64, Int64}, Tuple{Int64, Int64}, Tuple{typeof(identity), typeof(identity)}}, Tuple{FiniteDifferences.var"#Real_from_vec#20", FiniteDifferences.var"#Real_from_vec#20"}}(FiniteDifferences.var"#Tuple_from_vec#48"{Tuple{Int64, Int64}, Tuple{Int64, Int64}, Tuple{typeof(identity), typeof(identity)}}((1, 2), (1, 1), (identity, identity)), (FiniteDifferences.var"#Real_from_vec#20"(), FiniteDifferences.var"#Real_from_vec#20"())), FiniteDifferences.var"#Real_from_vec#20"(), FiniteDifferences.var"#Real_from_vec#20"())))

julia> from_vec(v)
ERROR: TypeError: in new, expected Int64, got a value of type Float64
Stacktrace:
 [1] macro expansion
   @ ~/.julia/packages/FiniteDifferences/W3rQO/src/to_vec.jl:0 [inlined]
 [2] _force_construct
   @ ~/.julia/packages/FiniteDifferences/W3rQO/src/to_vec.jl:27 [inlined]
 [3] (::FiniteDifferences.var"#structtype_from_vec#29"{StepRangeLen{Float64, Base.TwicePrecision{Float64}, Base.TwicePrecision{Float64}}, FiniteDifferences.var"#Tuple_from_vec#48"{NTuple{4, Int64}, NTuple{4, Int64}, NTuple{4, typeof(identity)}}, Tuple{FiniteDifferences.var"#structtype_from_vec#29"{Base.TwicePrecision{Float64}, FiniteDifferences.var"#Tuple_from_vec#48"{Tuple{Int64, Int64}, Tuple{Int64, Int64}, Tuple{typeof(identity), typeof(identity)}}, Tuple{FiniteDifferences.var"#Real_from_vec#20", FiniteDifferences.var"#Real_from_vec#20"}}, FiniteDifferences.var"#structtype_from_vec#29"{Base.TwicePrecision{Float64}, FiniteDifferences.var"#Tuple_from_vec#48"{Tuple{Int64, Int64}, Tuple{Int64, Int64}, Tuple{typeof(identity), typeof(identity)}}, Tuple{FiniteDifferences.var"#Real_from_vec#20", FiniteDifferences.var"#Real_from_vec#20"}}, FiniteDifferences.var"#Real_from_vec#20", FiniteDifferences.var"#Real_from_vec#20"}})(v::Vector{Float64})
   @ FiniteDifferences ~/.julia/packages/FiniteDifferences/W3rQO/src/to_vec.jl:53
 [4] top-level scope
   @ REPL[32]:1

caused by: MethodError: no method matching StepRangeLen{Float64, Base.TwicePrecision{Float64}, Base.TwicePrecision{Float64}}(::Base.TwicePrecision{Float64}, ::Base.TwicePrecision{Float64}, ::Float64, ::Float64)
Closest candidates are:
  StepRangeLen{T, R, S}(::R, ::S, ::Integer) where {T, R, S} at range.jl:359
  StepRangeLen{T, R, S}(::R, ::S, ::Integer, ::Integer) where {T, R, S} at range.jl:359
Stacktrace:
 [1] (::FiniteDifferences.var"#structtype_from_vec#29"{StepRangeLen{Float64, Base.TwicePrecision{Float64}, Base.TwicePrecision{Float64}}, FiniteDifferences.var"#Tuple_from_vec#48"{NTuple{4, Int64}, NTuple{4, Int64}, NTuple{4, typeof(identity)}}, Tuple{FiniteDifferences.var"#structtype_from_vec#29"{Base.TwicePrecision{Float64}, FiniteDifferences.var"#Tuple_from_vec#48"{Tuple{Int64, Int64}, Tuple{Int64, Int64}, Tuple{typeof(identity), typeof(identity)}}, Tuple{FiniteDifferences.var"#Real_from_vec#20", FiniteDifferences.var"#Real_from_vec#20"}}, FiniteDifferences.var"#structtype_from_vec#29"{Base.TwicePrecision{Float64}, FiniteDifferences.var"#Tuple_from_vec#48"{Tuple{Int64, Int64}, Tuple{Int64, Int64}, Tuple{typeof(identity), typeof(identity)}}, Tuple{FiniteDifferences.var"#Real_from_vec#20", FiniteDifferences.var"#Real_from_vec#20"}}, FiniteDifferences.var"#Real_from_vec#20", FiniteDifferences.var"#Real_from_vec#20"}})(v::Vector{Float64})
   @ FiniteDifferences ~/.julia/packages/FiniteDifferences/W3rQO/src/to_vec.jl:51
 [2] top-level scope
   @ REPL[32]:1