Needed type promotion for ForwardDiff.jl

Author: theogf

src/distances/dotproduct.jl

@@ -8,6 +8,8 @@ struct DotProduct <: Distances.PreMetric end
     return dot(a,b)
 end
 
+Distances.result_type(::DotProduct, Ta::Type, Tb::Type) = promote_type(Ta, Tb)
+
 @inline Distances.eval_op(::DotProduct, a::Real, b::Real) = a * b
 @inline (dist::DotProduct)(a::AbstractArray,b::AbstractArray) = Distances._evaluate(dist, a, b)
 @inline (dist::DotProduct)(a::Number,b::Number) = a * b

src/distances/sinus.jl

@@ -8,7 +8,9 @@ Distances.parameters(d::Sinus) = d.r
 @inline (dist::Sinus)(a::AbstractArray, b::AbstractArray) = Distances._evaluate(dist, a, b)
 @inline (dist::Sinus)(a::Number, b::Number) = abs2(sinpi(a - b) / first(dist.r))
 
-@inline function Distances._evaluate(d::Sinus, a::AbstractVector{T}, b::AbstractVector{T}) where {T}
+Distances.result_type(::Sinus{T}, Ta::Type, Tb::Type) where {T} = promote_type(T, Ta, Tb)
+
+@inline function Distances._evaluate(d::Sinus, a::AbstractVector, b::AbstractVector) where {T}
     @boundscheck if (length(a) != length(b)) || length(a) != length(d.r)
         throw(DimensionMismatch("Dimensions of the inputs are not matching : a = $(length(a)), b = $(length(b)), r = $(length(d.r))"))
     end