Destroying a struct object in C#?

Question

I am a bit confused about the fact that in C# only the reference types get garbage collected. That means GC picks only the reference types for memory de-allocation. So what

Answer 1

There are too many verbs used in this question, like destroyed, reclaimed, deallocated, removed. That doesn't correspond well with what actually happens. A local variable simply ceases to be, Norwegian parrot style.

A method has a single point of entry, first thing that happens is that the CPU stack pointer is adjusted. Creating a "stack frame", storage space for the local variables. The CLR guarantees that this space is initialized to 0, not otherwise a feature you use strongly in C# because of the definite assignment rule.

A method has a single point of exit, even if you method code is peppered with multiple return statements. At that point, the stack pointer is simply restored to its original value. In effect it "forgets" that the local variables where ever there. Their values are not 'scrubbed' in any way, the bytes are still there. But they won't last long, the next call in your program are going to overwrite them again. The CLR zero-initialization rule ensures that you can never observe those old values, that would be insecure.

Very, very fast, takes no more than a single processor cycle. A visible side-effect of this behavior in the C# language is that value types cannot have a finalizer. Ensuring no extra work has to be done.