HaloFour

public static class SynchronizationContextExtensions {
    public struct SynchronizationContextAwaiter : INotifyCompletion {
        private readonly SynchronizationContext context;

        public SynchronizationContextAwaiter(SynchronizationContext context) {
            this.context = context;
        }

        public bool IsCompleted {
            get { return (context == null); }

HaloFour

.assembly extern mscorlib {
  .publickeytoken = (B7 7A 5C 56 19 34 E0 89 )
  .ver 4:0:0:0
}
.assembly Covariance {
  .ver 1:0:0:0
}

.module Covariance.exe
.subsystem 0x0003

HaloFour

using System;
using System.Collections.Generic;
using System.Diagnostics;

public struct CompilerGeneratedArgs3 : IEnumerable<int>
{
    private struct Enumerator : IEnumerator<int>
    {
        private readonly CompilerGeneratedArgs3 args;
        private int index;