FlagsAttribute Enum problems

The definition of the shift operators means that only the 5 least significant bits are used for 32-bit numbers and only the first 6 bits for 64-bit; meaning:

1 << 5

is identical to

1 << 37

(both are 32)

By making it:

MsgrVersion9 = 1L << 32

you make it a 64-bit number, which is why @leppie’s fix works; otherwise the << is considered first (and note that 1<<32 is identical to 1<<0, i.e. 1), and then the resulting 1 is converted to a long; so it is still 1.

From §14.8 in the ECMA spec:

For the predefined operators, the number of bits to shift is computed as follows:

• When the type of x is int or uint, the shift count is given by the low-order five bits of count. In other words, the shift count is computed from count & 0x1F.
• When the type of x is long or ulong, the shift count is given by the low-order six bits of count. In other words, the shift count is computed from count & 0x3F.

If the resulting shift count is zero, the shift operators simply return the value of x.

Shift operations never cause overflows and produce the same results in checked and unchecked context