Use ProjectTo instead of _maybe_fix_to_composite

Author: devmotion

src/finite_difference_calls.jl

@@ -21,7 +21,7 @@ function _make_jvp_call(fdm, f, y, xs, ẋs, ignores)
     ignores = collect(ignores)
     all(ignores) && return ntuple(_ -> NoTangent(), length(xs))
     sigargs = zip(xs[.!ignores], ẋs[.!ignores])
-    return _maybe_fix_to_composite(y, jvp(fdm, f2, sigargs...))
+    return ProjectTo(y)(jvp(fdm, f2, sigargs...))
 end
 
 """
@@ -52,7 +52,7 @@ function _make_j′vp_call(fdm, f, ȳ, xs, ignores)
     @assert length(fd) == length(arginds)
 
     for (dx, ind) in zip(fd, arginds)
-        args[ind] = _maybe_fix_to_composite(xs[ind], dx)
+        args[ind] = ProjectTo(xs[ind])(dx)
     end
     return (args...,)
 end
@@ -87,15 +87,3 @@ function _wrap_function(f, xs, ignores)
     end
     return fnew
 end
-
-# TODO: remove after https://github.com/JuliaDiff/FiniteDifferences.jl/issues/97
-# For functions which return a tuple, FD returns a tuple to represent the differential. Tuple
-# is not a natural differential, because it doesn't overload +, so make it a Tangent.
-_maybe_fix_to_composite(::P, x::Tuple) where {P} = Tangent{P}(x...)
-_maybe_fix_to_composite(::P, x::NamedTuple) where {P} = Tangent{P}(; x...)
-function _maybe_fix_to_composite(
-    y::AbstractArray, x::AbstractArray{<:Union{Tuple,NamedTuple}}
-)
-    return map(_maybe_fix_to_composite, y, x)
-end
-_maybe_fix_to_composite(::Any, x) = x