supports_autoenzyme always false unless ext is loaded

ext/MeshIntegralsEnzymeExt.jl

@@ -16,4 +16,12 @@ function MeshIntegrals.jacobian(
     return Meshes.to.(Enzyme.jacobian(Enzyme.Forward, geometry, ts...))
 end
 
+# Supports all geometries except for a few
+# See GitHub Issue #154 for more information.
+supports_autoenzyme(::Type{<:Meshes.Geometry}) = true
+supports_autoenzyme(::Type{<:Meshes.BezierCurve}) = false
+supports_autoenzyme(::Type{<:Meshes.CylinderSurface}) = false
+supports_autoenzyme(::Type{<:Meshes.Cylinder}) = false
+supports_autoenzyme(::Type{<:Meshes.ParametrizedCurve}) = false
+
 end

src/utils.jl

@@ -18,11 +18,10 @@ end
 Return whether a geometry (or geometry type) has a parametric function that can be
 differentiated with Enzyme. See GitHub Issue #154 for more information.
 """
-supports_autoenzyme(::Type{<:Meshes.Geometry}) = true
-supports_autoenzyme(::Type{<:Meshes.BezierCurve}) = false
-supports_autoenzyme(::Type{<:Meshes.CylinderSurface}) = false
-supports_autoenzyme(::Type{<:Meshes.Cylinder}) = false
-supports_autoenzyme(::Type{<:Meshes.ParametrizedCurve}) = false
+function supports_autoenzyme end
+
+# Returns false on all geometries when Enzyme extension not loaded
+supports_autoenzyme(::Any) = false
 supports_autoenzyme(::G) where {G <: Geometry} = supports_autoenzyme(G)
 
 """
@@ -44,16 +43,24 @@ Return an instance of the default DifferentiationMethod for a particular geometr
 (or geometry type) and floating point type.
 """
 function _default_diff_method(
-        g::Type{G}, FP::Type{T}
+    ::Type{G},
+    FP::Type{T}
 ) where {G <: Geometry, T <: AbstractFloat}
-    if supports_autoenzyme(g) && FP <: Union{Float32, Float64}
+    # Enzyme only works with these FP types
+    EnzymeSupportedFPs = Union{Float32, Float64}
+
+    if supports_autoenzyme(G) && (FP <: EnzymeSupportedFPs)
         AutoEnzyme()
     else
         FiniteDifference()
     end
 end
 
-function _default_diff_method(::G, ::Type{T}) where {G <: Geometry, T <: AbstractFloat}
+# Re-run with the Geometry type as first argument
+function _default_diff_method(
+    ::G,
+    ::Type{T}
+) where {G <: Geometry, T <: AbstractFloat}
     _default_diff_method(G, T)
 end