On Wednesday, 31 December 2014 at 13:38:05 UTC, Shachar Shemesh
wrote:
alias dtype = void delegate(int i);
void func(T)( T d )
Try writing that:
void func(scope dtype d)
instead. Or (scope T d) should do it too if you need it to be
templated. The scope keyword tells the compiler that you promise
not to escape it from that scope, so it is safe to use stack
memory. Should prevent the copying to gc of a delegate. (One of
the few places the scope keyword is actually implemented to do
something!)
Alternatively, an alias parameter to the template can take a
predicate - assuming it is static - and generate a new function
for each one.
void func(alias pred)() {
foreach(i; 0 .. 10)
pred(i);
}
Then use it with func!(predicate)(). This is what Phobos
std.algorithm uses. It can be trickier to actually make it work
though.
But scope should get you to the next step easily. gdc might even
inline the delegate then, though I doubt dmd will. Even dmd ought
not to GC with it tho.
