On Fri, 30 Oct 2009 00:03:23 -0500, Daniel Keep
<daniel.keep.li...@gmail.com> wrote:
Phil Deets wrote:
Hi, is there a way to add members to an enum based on conditional
compilation symbols. I tried
enum Tag {
A, B,
version (symbol) {
C, D,
}
E,
}
but it doesn't work. I know I could do
version (symbol) {
enum Tag { A, B, C, D, E }
} else {
enum Tag { A, B, E }
}
but I don't want to do that since in my case, there can be quite a few
elements outside of the version, and I don't want to repeat them all.
template Version(char[] ident)
{
mixin(`version(`~ident~`) const Version = true;
else const Version = false;`);
}
char[] genEnum(bool flag1, bool flag2)
{
return "A, B, "
~ (flag1 ? "C, D, " : "")
~ "E, F, "
~ (flag2 ? "G, H, " : "")
~ "G, ";
}
mixin(genEnum( Version!(`symbol`), Version!(`somethingElse`) ));
... is about the best you can do, I think.
Hey, thanks for the idea. I worked with it a little bit to remove the
generator function and use multiline strings. This is what I came up with.
mixin(q"ENUM
enum Tag
{
A, B,
ENUM"~(Version!("symbol")?q"ENUM
C, D,
ENUM":"")~q"ENUM
E,
}
ENUM");
That's not pretty, but it's good enough for me.