C# numeric constants

Question

I have the following C# code:

byte rule = 0;
...
rule = rule | 0x80;

which produces the error:

Cannot implicitly convert type 'int' to 'byte'. An explicit conversion exists (are you missing a cast?)

[Update: first version of the question was wrong ... I misread the compiler output]

Adding the cast doesn't fix the problem:

rule = rule | (byte) 0x80;

I need to write it as:

rule |= 0x80;

Which just seems weird. Why is the |= operator any different to the | operator?

Is there any other way of telling the compiler to treat the constant as a byte?

---

@ Giovanni Galbo : yes and no. The code is dealing with the programming of the flash memory in an external device, and logically represents a single byte of memory. I could cast it later, but this seemed more obvious. I guess my C heritage is showing through too much!

@ Jonathon Holland : the 'as' syntax looks neater but unfortunately doesn't appear to work ... it produces:

The as operator must be used with a reference type or nullable type ('byte' is a non-nullable value type)

Answer 1

C# does not have a literal suffix for byte. u = uint, l = long, ul = ulong, f = float, m = decimal, but no byte. You have to cast it.

Answer 2

This works:

rule = (byte)(rule | 0x80);

Apparently the expression 'rule | 0x80' returns an int even if you define 0x80 as 'const byte 0x80'.