TrustRegion -> SimpleTrustRegion and specialize the number types

Author: ChrisRackauckas

src/trustRegion.jl

@@ -1,6 +1,6 @@
 """
 ```julia
-TrustRegion(max_trust_radius::Number; chunk_size = Val{0}(),
+SimpleTrustRegion(max_trust_radius::Number; chunk_size = Val{0}(),
                                autodiff = Val{true}(), diff_type = Val{:forward})
 ```
 
@@ -49,16 +49,16 @@ solver
 - `max_shrink_times`: the maximum number of times to shrink the trust region radius in a
   row, `max_shrink_times` is exceeded, the algorithm returns. Defaults to `32`.
 """
-struct TrustRegion{CS, AD, FDT} <: AbstractNewtonAlgorithm{CS, AD, FDT}
-    max_trust_radius::Number
-    initial_trust_radius::Number
-    step_threshold::Number
-    shrink_threshold::Number
-    expand_threshold::Number
-    shrink_factor::Number
-    expand_factor::Number
+struct SimpleTrustRegion{T, CS, AD, FDT} <: AbstractNewtonAlgorithm{CS, AD, FDT}
+    max_trust_radius::T
+    initial_trust_radius::T
+    step_threshold::T
+    shrink_threshold::T
+    expand_threshold::T
+    shrink_factor::T
+    expand_factor::T
     max_shrink_times::Int
-    function TrustRegion(max_trust_radius::Number; chunk_size = Val{0}(),
+    function SimpleTrustRegion(max_trust_radius::Number; chunk_size = Val{0}(),
                          autodiff = Val{true}(),
                          diff_type = Val{:forward},
                          initial_trust_radius::Number = max_trust_radius / 11,
@@ -68,8 +68,9 @@ struct TrustRegion{CS, AD, FDT} <: AbstractNewtonAlgorithm{CS, AD, FDT}
                          shrink_factor::Number = 0.25,
                          expand_factor::Number = 2.0,
                          max_shrink_times::Int = 32)
-        new{SciMLBase._unwrap_val(chunk_size), SciMLBase._unwrap_val(autodiff),
-            SciMLBase._unwrap_val(diff_type)}(max_trust_radius, initial_trust_radius,
+        new{typeof(initial_trust_radius), SciMLBase._unwrap_val(chunk_size), 
+            SciMLBase._unwrap_val(autodiff), SciMLBase._unwrap_val(diff_type)}(
+                                              max_trust_radius, initial_trust_radius,
                                               step_threshold,
                                               shrink_threshold, expand_threshold,
                                               shrink_factor,
@@ -78,7 +79,7 @@ struct TrustRegion{CS, AD, FDT} <: AbstractNewtonAlgorithm{CS, AD, FDT}
 end
 
 function SciMLBase.__solve(prob::NonlinearProblem,
-                           alg::TrustRegion, args...; abstol = nothing,
+                           alg::SimpleTrustRegion, args...; abstol = nothing,
                            reltol = nothing,
                            maxiters = 1000, kwargs...)
     f = Base.Fix2(prob.f, prob.p)