Converting a multivariate function to a single variate function

[nilshg]

Why is the splat operator slow?

I was doing some benchmarks and got these results: julia> using BenchmarkTools julia> f1(itr) = collect(itr) f1 (generic function with 1 method) julia> f2(itr) = [itr...] f2 (generic function with 1 method) julia> gen = (x for x in 1:1000) Base.Generator{UnitRange{Int64}, typeof(identity)}(identity, 1:1000) julia> @btime f1($gen); 910.000 ns (1 allocation: 7.94 KiB) julia> @btime f2($gen); 80.200 μs (1988 allocations: 84.44 KiB) Why is the splat operator slower than the collect functi…