#include <iostream>
enum Enum {ZERO, A, B, C, D};
Enum operator|(Enum a, Enum b) { return Enum(int(a)|int(b)); }
int main() {
Enum a(A);
Enum b(B);
Enum c = a|b;
std::cout << a << ',' << b << ',' << c << std::endl;
}
Wander Lairson Costa wrote:
2013/10/4 Thiago Macieira <thiago.macie...@intel.com>:
On sexta-feira, 4 de outubro de 2013 09:09:32, Wander Lairson Costa wrote:
The issued raised when I took code from window.c in the weston clients:
mask = xkb_state_serialize_mods(input->xkb.state,
XKB_STATE_DEPRESSED |
XKB_STATE_LATCHED);
g++ gave me a build error because I was passing an integer to enum
parameter. C++ is a bit more nit-picky than C regarding implicit
conversions. Therefore I had to use a cast.
Like you said, it's window.c. Why are you copy & pasting C code into a C++
file?
Well, weston clients are the only code reference I had in hand.
Sometimes I go to qtwayland also, but it did not run away from the
casts...
With the ABI that GCC uses, it's always at least 4 bytes.
Personally, I don't like enum's in the ABI at all, because according
to C/C++ standards, the compiler is free to choose whatever type it
likes, and indeed I had problems with that in the past. C++11 fixed
that [1]. But nevermind.
We're not relying on the ABI. I said "The enum must be backed by an integer
with at least as many bits as the enum possesses.". If you cast back from an
int that contains one of the enum values or an OR combination of enum values,
it *will* fit.
I think I caused more confusion than explained here. My original point
was not if the value fits or not, but that once you do whatever math
with the enum, the result is not an enum type anymore (yes, sounds
nit-picky)...
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