EmittingILToCreateObject.cs

private static Dictionary<Type, Func<IntPtr, bool, object>> constructorCache =
    new Dictionary<Type, Func<IntPtr, bool, object>>();
 
private static Func<IntPtr, bool, object> CreateConstructorDelegate<T>()
{
    // We need to first grab the reflection information for the more derrived type we're casting to.
    // SWIG has protected constructors we'll be able to call that take 2 parameters, the native pointer
    // to the type and whether or not SWIG owns the memory
    ConstructorInfo ctor = typeof(T).GetConstructor(
        BindingFlags.Instance | BindingFlags.NonPublic, null,
        CallingConventions.HasThis, new Type[] { typeof(IntPtr), typeof(bool) }, null);
 
    // Lets emit some IL that will allow us to construct our type much
    // faster than using reflection.
    DynamicMethod dm = new DynamicMethod("Create", typeof(object),
        new Type[] { typeof(IntPtr), typeof(bool) }, typeof(T), true);
    ILGenerator il = dm.GetILGenerator();
    il.Emit(OpCodes.Ldarg_0);
    il.Emit(OpCodes.Ldarg_1);
    il.Emit(OpCodes.Newobj, ctor);
    il.Emit(OpCodes.Ret);
 
    // Create the delegate for the dynamic method, which will further improve the calling speed.
    return (Func<IntPtr, bool, object>)dm.CreateDelegate(typeof(Func<IntPtr, bool, object>));
}