Thursday, March 26, 2009
Buffer vs. Array
To clear up any misconceptions, System.Array.Copy is not the same as System.Buffer.BlockCopy unless you're operating on arrays of System.Byte. The Buffer class copies bytes from one array to another. If you have an array of System.Int32 (4 bytes each) and you copy 3 bytes (not items) from your source to your destination array, you will just get the first 3 bytes of your 4 byte System.Int32. Depending on the endian-ness of your system, this could give you different results. Also, the System.Buffer class only works on primitives. Not C# primitives (which include strings) and not even derivatives of System.ValueType (e.g. enums and your own structs). Clearly it can't work on reference types safely (imagine just copying 3 of the 4 bytes from one object reference to another) but I would have expected it to work with enumerations (essentially ints).
Posted by Jono at Thursday, March 26, 2009