"IEnumerable should not be forced to return a type-erased = heap allocated IEnumerator instance."
Foreach loops use compile-time duck typing, so if you don't intend to use your enumerable in LINQ then both the enumerable and enumerator don't need to implement any interfaces.
This optimisation covers only one common use case, but that's the way of things in C# land.
Foreach loops use compile-time duck typing, so if you don't intend to use your enumerable in LINQ then both the enumerable and enumerator don't need to implement any interfaces.
This optimisation covers only one common use case, but that's the way of things in C# land.