Consistent return type from lstirling_asym(x::Float32) (#141)

* Consistent return type from `lstirling_asym(x::Float32)`

As described in #140

* Avoid broadcasting

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

* Add tests

* Add newline

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

src/misc.jl

@@ -66,7 +66,7 @@ lstirling_asym(x::BigFloat) = loggamma(x) + x - log(x)*(x - big(0.5)) - log2π/b
 lstirling_asym(x::Integer) = lstirling_asym(float(x))
 
 const lstirlingF64 = Float64[lstirling_asym(k) for k in big(1):big(64)]
-const lstirlingF32 = Float64[lstirling_asym(k) for k in big(1):big(40)]
+const lstirlingF32 = [Float32(lstirlingF64[i]) for i in 1:40]
 
 function lstirling_asym(x::Float64)
     isinteger(x) && (0 < x ≤ length(lstirlingF64)) && return lstirlingF64[Int(x)]

test/misc.jl

@@ -70,3 +70,10 @@ end
         @test isone(binompdf(n, p, k))
     end
 end
+
+@testset "lstirling_asym" begin
+    # can test for equality here because the lhs is the way the value is created
+    @test Float32(lstirling_asym(1.0)) == @inferred lstirling_asym(1.0f0)
+    # for 64.0f0 the expansion is used but for 64.0 the BigFloat value is rounded
+    @test Float32(lstirling_asym(64.0)) ≈ @inferred lstirling_asym(64.0f0)
+end