More flexible types for inplace operations

Author: theogf

src/kernelmatrix.jl

@@ -1,5 +1,5 @@
 
-function _kappamatrix!(κ::Kernel{T}, P::AbstractMatrix{T}) where {T<:Real}
+function _kappamatrix!(κ::Kernel{T}, P::AbstractMatrix{T₁}) where {T<:Real,T₁<:Real}
     for i in eachindex(P)
         @inbounds P[i] = kappa(κ, P[i])
     end
@@ -8,9 +8,9 @@ end
 
 function _symmetric_kappamatrix!(
         κ::Kernel{T},
-        P::AbstractMatrix{T},
+        P::AbstractMatrix{T₁},
         symmetrize::Bool
-    ) where {T<:Real}
+    ) where {T<:Real,T₁<:Real}
     if !((n = size(P,1)) == size(P,2))
         throw(DimensionMismatch("Pairwise matrix must be square."))
     end

src/kernels/squaredexponential.jl

@@ -37,8 +37,8 @@ function SquaredExponentialKernel(α::Union{T,AbstractVector{T}}=1.0) where {T<:
     SquaredExponentialKernel{promote_float(T)}(α)
 end
 
-@inline kappa(κ::SquaredExponentialKernel{T,<:Real}, d²::T) where {T} = exp(-κ.α*d²)
-@inline kappa(κ::SquaredExponentialKernel{T}, d²::T) where {T} = exp(-d²)
+@inline kappa(κ::SquaredExponentialKernel{T,<:Real}, d²::Real) where {T} = exp(-κ.α*d²)
+@inline kappa(κ::SquaredExponentialKernel{T}, d²::Real) where {T} = exp(-d²)
 
 function convert(
         ::Type{K},