Discussion on: What the heck is Currying anyway?

IL_0000: ldarg.0      // a
IL_0001: ldarg.1      // b
IL_0002: add
IL_0003: ldarg.2      // c
IL_0004: add
IL_0005: ldarg.3      // d
IL_0006: add
IL_0007: ret

// function call
IL_0000: ldc.i4.1
IL_0001: ldc.i4.2
IL_0002: ldc.i4.3
IL_0003: ldc.i4.4
IL_0004: call  int32 CurryDemo.BenchmarkNormalVsCurry::NormalAdd(int32, int32, int32, int32)

IL_0000: newobj  instance void CurryDemo.BenchmarkNormalVsCurry/'<>c__DisplayClass1_0'::.ctor()
IL_0005: dup
IL_0006: ldarg.0      // a
IL_0007: stfld  int32 CurryDemo.BenchmarkNormalVsCurry/'<>c__DisplayClass1_0'::a

IL_000c: ldftn  instance class [System.Runtime]System.Func`2<int32, class [System.Runtime]System.Func`2<int32, int32>> CurryDemo.BenchmarkNormalVsCurry/'<>c__DisplayClass1_0'::'<CurryAdd>b__0'(int32)
IL_0012: newobj  instance void class [System.Runtime]System.Func`2<int32, class [System.Runtime]System.Func`2<int32, class [System.Runtime]System.Func`2<int32, int32>>>::.ctor(object, native int)
IL_0017: ret

// function call
IL_0000: ldc.i4.1
IL_0001: call         class [System.Runtime]System.Func`2<int32, class [System.Runtime]System.Func`2<int32, class [System.Runtime]System.Func`2<int32, int32>>> CurryDemo.BenchmarkNormalVsCurry::CurryAdd(int32)
IL_0006: ldc.i4.2
IL_0007: callvirt     instance !1/*class [System.Runtime]System.Func`2<int32, class [System.Runtime]System.Func`2<int32, int32>>*/ class [System.Runtime]System.Func`2<int32, class [System.Runtime]System.Func`2<int32, class [System.Runtime]System.Func`2<int32, int32>>>::Invoke(!0/*int32*/)
IL_000c: ldc.i4.3
IL_000d: callvirt     instance !1/*class [System.Runtime]System.Func`2<int32, int32>*/ class [System.Runtime]System.Func`2<int32, class [System.Runtime]System.Func`2<int32, int32>>::Invoke(!0/*int32*/)
IL_0012: ldc.i4.4
IL_0013: callvirt     instance !1/*int32*/ class [System.Runtime]System.Func`2<int32, int32>::Invoke(!0/*int32*/)

// * Summary *

BenchmarkDotNet=v0.12.1, OS=Windows 10.0.19041.450 (2004/?/20H1)
AMD Ryzen 7 3800X, 1 CPU, 16 logical and 8 physical cores
.NET Core SDK=3.1.401
  [Host]        : .NET Core 3.1.7 (CoreCLR 4.700.20.36602, CoreFX 4.700.20.37001), X64 RyuJIT
  .NET Core 3.1 : .NET Core 3.1.7 (CoreCLR 4.700.20.36602, CoreFX 4.700.20.37001), X64 RyuJIT

Job=.NET Core 3.1  Runtime=.NET Core 3.1

|        Method |       Mean |     Error |    StdDev |
|-------------- |-----------:|----------:|----------:|
| TestNormalAdd |  0.0203 ns | 0.0093 ns | 0.0083 ns |
|  TestCurryAdd | 33.1419 ns | 0.2941 ns | 0.2607 ns |

// * Hints *
Outliers
  BenchmarkNormalVsCurry.TestNormalAdd: .NET Core 3.1 -> 1 outlier  was  removed (1.57 ns)
  BenchmarkNormalVsCurry.TestCurryAdd: .NET Core 3.1  -> 1 outlier  was  removed, 2 outliers were detected (33.77 ns, 35.37 ns)

// * Legends *
  Mean   : Arithmetic mean of all measurements
  Error  : Half of 99.9% confidence interval
  StdDev : Standard deviation of all measurements
  1 ns   : 1 Nanosecond (0.000000001 sec)

// ***** BenchmarkRunner: End *****

    class Program
    {
        static void Main(string[] args)
        {
            var summary = BenchmarkRunner.Run<BenchmarkNormalVsCurry>();
        }
    }

    [SimpleJob(RuntimeMoniker.NetCoreApp31)]
    [RPlotExporter]
    public class BenchmarkNormalVsCurry
    {
        public static int NormalAdd(int a, int b, int c, int d)
        {
            return a + b + c + d;
        }

        public static Func<int, Func<int, Func<int, int>>> CurryAdd(int a) =>
            (b) =>
                (c) =>
                    (d) => a + b + c + d;

        [Benchmark]
        public void TestNormalAdd() => NormalAdd(1, 2, 3, 4);

        [Benchmark]
        public void TestCurryAdd() => CurryAdd(1)(2)(3)(4);
    }