Why can't I do boolean logic on bytes?

Question

In C# (3.5) I try the following:

byte byte1 = 0x00;
byte byte2 = 0x00;
byte byte3 = byte1 & byte2;

and I get Error 132: "Cannot implicitly convert type 'int' to 'byte'. An explicit conversion exists (are you missing a cast?)". The same happens with | and ^.

What am I doing wrong? Why is it asking me about ints? Why can't I do boolean logic on bytes?

Answer 1

Various operators aren't declared for byte - both operands get promoted to int, and the result is int. For example, addition:

byte byte1 = 0x00;
byte byte2 = 0x00;
byte byte3 = byte1 + byte2; // Compilation error

Note that compound assignments do work:

byte1 += byte2;

There was a recent SO question on this. I agree this is particularly irksome for bitwise operations though, where the result should always be the same size, and it's a logically entirely valid operation.

As a workaround, you can just cast the result back to byte:

byte byte3 = (byte) (byte1 & byte2);