add backwards compatability via a Val dispatch

Author: ChrisRackauckas

Project.toml

@@ -1,7 +1,7 @@
 name = "PreallocationTools"
 uuid = "d236fae5-4411-538c-8e31-a6e3d9e00b46"
 authors = ["Chris Rackauckas <accounts@chrisrackauckas.com>"]
-version = "0.2.1"
+version = "0.2.2"
 
 [deps]
 Adapt = "79e6a3ab-5dfb-504d-930d-738a2a938a0e"

src/PreallocationTools.jl

@@ -25,12 +25,13 @@ or specifying an array of chunk_sizes.
 """
 dualcache(u::AbstractArray, N::Int=ForwardDiff.pickchunksize(length(u)); levels::Int = 1) = DiffCache(u, size(u), N*ones(Int, levels))
 dualcache(u::AbstractArray, N::AbstractArray{<:Int}) = DiffCache(u, size(u), N)
+dualcache(u::AbstractArray, ::Val{N}; levels::Int = 1) where N = dualcache(u,N;levels)
 
 """
 
 `get_tmp(dc::DiffCache, u)`
 
-Returns the `Dual` or normal cache array stored in `dc` based on the type of `u`. 
+Returns the `Dual` or normal cache array stored in `dc` based on the type of `u`.
 
 """
 function get_tmp(dc::DiffCache, u::T) where T<:ForwardDiff.Dual
@@ -63,7 +64,7 @@ get_tmp(dc::DiffCache, u::AbstractArray) = dc.du
 
 function enlargedualcache!(dc, nelem) #warning comes only once per dualcache.
     chunksize = div(nelem, length(dc.du)) - 1
-    @warn "The supplied dualcache was too small and was enlarged. This incurrs allocations 
+    @warn "The supplied dualcache was too small and was enlarged. This incurrs allocations
     on the first call to get_tmp. If few calls to get_tmp occur and optimal performance is essential,
     consider changing 'N'/chunk size of this dualcache to $chunksize."
     resize!(dc.dual_du, nelem)