On Tuesday, 3 April 2018 at 18:57:29 UTC, WebFreak001 wrote:
you need to use a static foreach for this. You can insert a
static foreach basically where you can insert a function
definition like void foo() {}
foreach is more like a function call like foo(), so you can't
put it in the mixin template.
A mixin template is basically expected to be mixin-able in
global scope or in a class/struct so it can't have any things
like function calls because that would be the same as writing
`foo();` at global level instead of in the main function.
static foreach on the other hand allows exactly that because it
literally unrolls the contents and inserts it multiple times,
so you can also put it in mixin templates if the content of the
loop is valid in mixin templates.
If you need to support older compilers you can use normal
foreach with ctfe by generating a code string or do recursive
templates, but I would really encourage you to use static
foreach instead, it is cleaner and faster.
I think, the OP has something other in mind. Look at this:
´´´
void main(){}
struct World
{
float rotation;
bool active;
//mixin BuildStuff!();
}
mixin BuildStuff!();
mixin template BuildStuff()
{
static foreach(elem; __traits(allMembers, World))
{
pragma(msg, elem);
}
}
´´´
While the outer mixin works as expected, the inner one results in
a seg fault.
No idea why, however, too...
