On Thursday, 21 December 2017 at 16:38:36 UTC, Anonymouse wrote:
On Thursday, 21 December 2017 at 16:25:00 UTC, Marc wrote:
For example, I'd like to declare a variable inside a static
foreach like in below code, just for better organization,
otherwise, I have to use the value directly instead of the
variable. If the value is used more than once, it might be
inviable.
enum allMembers = __traits(derivedMembers, C);
static foreach(enum string member; allMembers) {
enum attributes = __traits(getAttributes,
__traits(getMember, C, member));
static foreach(C c; attributes) {
writeln(c);
}
}
I got redefinition erros of "atributes" on this. Can I have
this only at compile time?
I don't think you need static for foreach of __traits
allMembers/derivedMembers and .tupleof. It unrolls at
compile-time and builds fine for me if I just remove the
statics. https://run.dlang.io/is/Ln3kVZ
/*static*/ foreach(C c; attributes)
Mind that c will not be of type C but of the type of the
attribute.
The trick with static foreach is to create a new scope:
https://run.dlang.io/is/wODA0x
DIP1010 [1] suggested __local but while this is implemented, it
it's not exposed yet.
There's also a bit of discussion about this at [2].
[1]
https://github.com/dlang/DIPs/blob/master/DIPs/DIP1010.md#local-declarations
[2] https://github.com/dlang/phobos/pull/5729
