As you know if you've read this blog for a while, I'm disturbed by the myth that "value types go on the stack". Unfortunately, there are plenty of examples in our own documentation and in many books that reinforce this myth, either subtly or overtly. I'm opposed to it because:
The way in the past I've usually pushed back on this myth is to say that the real statement should be "in the Microsoft implementation of C# on the desktop CLR, value types are stored on the stack when the value is a local variable or temporary that is not a closed-over local variable of a lambda or anonymous method, and the method body is not an iterator block, and the jitter chooses to not enregister the value." Read more: Fabulous Adventures In Coding
- It is usually stated incorrectly: the statement should be "value types can be stored on the stack", instead of the more common "value types are always stored on the stack".
- It is almost always irrelevant. We've worked hard to make a managed environment where the distinctions between different kinds of storage are hidden from the user. Unlike some languages, in which you must know whether a particular storage is on the stack or the heap for correctness reasons.
- It is incomplete. What about references? References are neither value types nor instances of reference types, but they are values. They've got to be stored somewhere. Do they go on the stack or the heap? Why does no one ever talk about them? Just because they don't have a type in the C# type system is no reason to ignore them.
The way in the past I've usually pushed back on this myth is to say that the real statement should be "in the Microsoft implementation of C# on the desktop CLR, value types are stored on the stack when the value is a local variable or temporary that is not a closed-over local variable of a lambda or anonymous method, and the method body is not an iterator block, and the jitter chooses to not enregister the value." Read more: Fabulous Adventures In Coding
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