copy rand_tangent(::BigFloat) from ChainRulesTestUtils (#155)

Author: mzgubic

src/rand_tangent.jl

@@ -13,6 +13,10 @@ rand_tangent(rng::AbstractRNG, x::Integer) = DoesNotExist()
 
 rand_tangent(rng::AbstractRNG, x::T) where {T<:Number} = randn(rng, T)
 
+# TODO: right now Julia don't allow `randn(rng, BigFloat)` 
+# see: https://github.com/JuliaLang/julia/issues/17629
+rand_tangent(rng::AbstractRNG, ::BigFloat) = big(randn(rng))
+
 rand_tangent(rng::AbstractRNG, x::StridedArray) = rand_tangent.(Ref(rng), x)
 
 function rand_tangent(rng::AbstractRNG, x::T) where {T<:Tuple}

test/rand_tangent.jl

@@ -15,6 +15,7 @@ using FiniteDifferences: rand_tangent
         # Numbers.
         (5.0, Float64),
         (5.0 + 0.4im, Complex{Float64}),
+        (big(5.0), BigFloat),
 
         # StridedArrays.
         (randn(Float32, 3), Vector{Float32}),