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Possible Duplicate:
Do generic interfaces in C# prevent boxing? (.NET vs Mono performance)

I have one quick question... by using generics, do I completely get rid of boxing/unboxing operations?

For example, by using a List do I still get lots of boxing/unboxing?

I've read several docs on the internet but couldn't solve this specific question...

Community
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Paulo
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2 Answers2

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If a class was written correctly, then using generics will avoid all boxing and unboxing. Instead, the just-in-time compiler will generate code for each version of the class that correctly handles the value types appropriately.

Jeffrey L Whitledge
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    +1 for explicitly mentioning value types. – overslacked Mar 10 '10 at 23:55
  • -1 a class was/is never boxed or unboxed - boxing is for value types only. The advantage of generics for class objects is strong typing, not no-boxing. – pm100 Mar 11 '10 at 01:22
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    @pm100 : by "each version of the class" I mean the generic class. It has a different version for each type supplied as a parameter. The JIT creates different code for each value type supplied. It also creates a single version that handles all of the reference types. – Jeffrey L Whitledge Mar 11 '10 at 01:39
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If you use it correctly then: Yes, it will eliminate boxing.

For instance, 

List<int> table = new List<int>();
table.Add(1);
int x = table[0];

does not involve any boxing/unboxing.

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