Merge pull request #1100 from SciML/forwardidff_emptykwargs

Handle empty Kwargs case in forwarddiff detection

Author: ChrisRackauckas

src/forwarddiff.jl

@@ -363,11 +363,14 @@ function anyeltypedual(x::NamedTuple, ::Type{Val{counter}} = Val{0}) where {coun
     anyeltypedual(values(x))
 end
 
-function DiffEqBase.anyeltypedual(
+function anyeltypedual(
         f::SciMLBase.AbstractSciMLFunction, ::Type{Val{counter}}) where {counter}
     Any
 end
 
+anyeltypedual(::@Kwargs{}, ::Type{Val{counter}} = Val{0}) where {counter} = Any
+anyeltypedual(::Type{@Kwargs{}}, ::Type{Val{counter}} = Val{0}) where {counter} = Any
+
 @inline promote_u0(::Nothing, p, t0) = nothing
 
 @inline function promote_u0(u0, p, t0)

test/forwarddiff_dual_detection.jl

@@ -162,7 +162,7 @@ for p in p_possibilities_missed
 end
 
 p_possibilities_notdual = [
-    (), (;), [2.0], [2.0, 2], [2.0, (2.0)], [2.0, MyStruct(2.0, 2.0f0)]
+    (), (;), [2.0], [2.0, 2], [2.0, (2.0)], [2.0, MyStruct(2.0, 2.0f0)], pairs((;))
 ]
 
 for p in p_possibilities_notdual