Compares the difference between Action<T> and Func<T,bool> where we ignore the return value.

Action.cs

using System;

public static class Program
{
  public static void Main(string[] args)
	{
		var m = new Action<int>(i => Console.WriteLine(i.ToString()));
		m(5);
	}
}

Action.il

.class public auto ansi abstract sealed beforefieldinit Program
  extends [mscorlib]System.Object
{
	// Fields
	.field private static class [mscorlib]System.Action`1<int32> 'CS$<>9__CachedAnonymousMethodDelegate1'
	.custom instance void [mscorlib]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = (
		01 00 00 00
	)

	// Methods
	.method public hidebysig static 
		void Main (
			string[] args
		) cil managed 
	{
		// Method begins at RVA 0x2060
		// Code size 42 (0x2a)
		.maxstack 2
		.entrypoint
		.locals init (
			[0] class [mscorlib]System.Action`1<int32>
		)

		IL_0000: nop
		IL_0001: ldsfld class [mscorlib]System.Action`1<int32> Program::'CS$<>9__CachedAnonymousMethodDelegate1'
		IL_0006: brtrue.s IL_001b

		IL_0008: ldnull
		IL_0009: ldftn void Program::'<Main>b__0'(int32)
		IL_000f: newobj instance void class [mscorlib]System.Action`1<int32>::.ctor(object, native int)
		IL_0014: stsfld class [mscorlib]System.Action`1<int32> Program::'CS$<>9__CachedAnonymousMethodDelegate1'
		IL_0019: br.s IL_001b

		IL_001b: ldsfld class [mscorlib]System.Action`1<int32> Program::'CS$<>9__CachedAnonymousMethodDelegate1'
		IL_0020: stloc.0
		IL_0021: ldloc.0
		IL_0022: ldc.i4.5
		IL_0023: callvirt instance void class [mscorlib]System.Action`1<int32>::Invoke(!0)
		IL_0028: nop
		IL_0029: ret
	} // end of method Program::Main

	.method private hidebysig static 
		void '<Main>b__0' (
			int32 i
		) cil managed 
	{
		.custom instance void [mscorlib]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = (
			01 00 00 00
		)
		// Method begins at RVA 0x2050
		// Code size 14 (0xe)
		.maxstack 8





		IL_0000: ldarga.s i
		IL_0002: call instance string [mscorlib]System.Int32::ToString()
		IL_0007: call void [mscorlib]System.Console::WriteLine(string)
		IL_000c: nop
		IL_000d: ret






	} // end of method Program::'<Main>b__0'

} // end of class Program

Func.cs

using System;

public static class Program
{
  public static void Main(string[] args)
	{
		Func<int,bool> m = (i) => { Console.WriteLine(i.ToString()); return true; };
		m(5);
	}
}

Func.il

.class public auto ansi abstract sealed beforefieldinit Program
  extends [mscorlib]System.Object
{
	// Fields
	.field private static class [mscorlib]System.Func`2<int32, bool> 'CS$<>9__CachedAnonymousMethodDelegate1'
	.custom instance void [mscorlib]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = (
		01 00 00 00
	)

	// Methods
	.method public hidebysig static 
		void Main (
			string[] args
		) cil managed 
	{
		// Method begins at RVA 0x2070
		// Code size 42 (0x2a)
		.maxstack 2
		.entrypoint
		.locals init (
			[0] class [mscorlib]System.Func`2<int32, bool>
		)

		IL_0000: nop
		IL_0001: ldsfld class [mscorlib]System.Func`2<int32, bool> Program::'CS$<>9__CachedAnonymousMethodDelegate1'
		IL_0006: brtrue.s IL_001b

		IL_0008: ldnull
		IL_0009: ldftn bool Program::'<Main>b__0'(int32)
		IL_000f: newobj instance void class [mscorlib]System.Func`2<int32, bool>::.ctor(object, native int)
		IL_0014: stsfld class [mscorlib]System.Func`2<int32, bool> Program::'CS$<>9__CachedAnonymousMethodDelegate1'
		IL_0019: br.s IL_001b

		IL_001b: ldsfld class [mscorlib]System.Func`2<int32, bool> Program::'CS$<>9__CachedAnonymousMethodDelegate1'
		IL_0020: stloc.0
		IL_0021: ldloc.0
		IL_0022: ldc.i4.5
		IL_0023: callvirt instance !1 class [mscorlib]System.Func`2<int32, bool>::Invoke(!0)
		IL_0028: pop
		IL_0029: ret
	} // end of method Program::Main

	.method private hidebysig static 
		bool '<Main>b__0' (
			int32 i
		) cil managed 
	{
		.custom instance void [mscorlib]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = (
			01 00 00 00
		)
		// Method begins at RVA 0x2050
		// Code size 20 (0x14)
		.maxstack 1
		.locals init (
			[0] bool
		)

		IL_0000: nop
		IL_0001: ldarga.s i
		IL_0003: call instance string [mscorlib]System.Int32::ToString()
		IL_0008: call void [mscorlib]System.Console::WriteLine(string)
		IL_000d: nop

		IL_000e: ldc.i4.1
		IL_000f: stloc.0
		IL_0010: br.s IL_0012

		IL_0012: ldloc.0
		IL_0013: ret
	} // end of method Program::'<Main>b__0'

} // end of class Program