try inlining to eliminate allocations (#155)

* try inlining to eliminate allocations

* Update test/runtests.jl

Co-authored-by: David Müller-Widmann <devmotion@users.noreply.github.com>

---------

Co-authored-by: David Müller-Widmann <devmotion@users.noreply.github.com>

Author: tpapp

src/special_arrays.jl

@@ -352,7 +352,7 @@ $(SIGNATURES)
 
 Implementation of Cholesky factor calculation.
 """
-function calculate_corr_cholesky_factor!(U::AbstractMatrix{T}, flag::LogJacFlag,
+@inline function calculate_corr_cholesky_factor!(U::AbstractMatrix{T}, flag::LogJacFlag,
                                           x::AbstractVector, index::Int) where {T<:Real}
     n = size(U, 1)
     ℓ = logjac_zero(flag, T)

test/runtests.jl

@@ -819,6 +819,11 @@ end
             @test inverse(t, y) ≈ x
         end
     end
+
+    # allocations
+    t7 = corr_cholesky_factor(SMatrix{7,7})
+    z7 = zeros(dimension(t7))
+    @test iszero(((t, z) -> @allocations(transform(t, z)))(t7, z7))
 end
 
 @testset "corr cholesky factor large inputs" begin