Fix method ambiguity for Base.TwicePrecision

JuliaDiff · Oct 29, 2024 · 37786e5 · 37786e5
1 parent ec74fbc
commit 37786e5
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diff --git a/src/dual.jl b/src/dual.jl
@@ -78,6 +78,10 @@ end
 @inline Dual{T,V,N}(x::Number) where {T,V,N} = convert(Dual{T,V,N}, x)
 @inline Dual{T,V}(x) where {T,V} = convert(Dual{T,V}, x)
 
+# Fix method ambiguity issue by adapting the definition in Base to `Dual`s
+Dual{T,V,N}(x::Base.TwicePrecision) where {T,V,N} =
+    (Dual{T,V,N}(x.hi) + Dual{T,V,N}(x.lo))::Dual{T,V,N}
+
 ##############################
 # Utility/Accessor Functions #
 ##############################

diff --git a/test/DualTest.jl b/test/DualTest.jl
@@ -667,4 +667,8 @@ end
     @test ForwardDiff.derivative(float, 1)::Float64 === 1.0
 end
 
+@testset "TwicePrecision" begin
+    @test ForwardDiff.derivative(x -> sum(1 .+ x .* (0:0.1:1)), 1) == 5.5
+end
+
 end # module