On Friday, 28 June 2013 at 13:20:47 UTC, monarch_dodra wrote:
What is a "string lambda" ? Do you mean "a string alias latter
parsed as an expression", or "an actual lambda function".
The former. I didn't think it was *that* obscure of a term
(https://www.google.com/search?q=%22string+lambda%22+site:forum.dlang.org).
There were talks about this recently in learn: If you *type*
the same lambda function twice, it *will* generate two
different templates.
http://forum.dlang.org/thread/[email protected]
I'm not sure if that's due to this bug or not:
http://forum.dlang.org/thread/[email protected]?page=2#post-jdcn98:241mg9:244:40digitalmars.com
However,
--------
enum PRED = () => 1;
struct S(alias pred){}
void main()
{
auto a = S!PRED();
auto b = S!PRED();
a = b;
}
--------
This is fine.
If that's all it takes to avoid copies, then maybe it's not so
big of a problem for lambdas.
From testing, *string* preds don't have this "feature"/"bug"
(?), even if you compile time build them, the compiler will
"see" that it is the same string (probably true for integrals
and whatnot). But for lambdas, only their *name* counts (eg
__lambda1__). So if you plan to re-use a lambda, it *must* be
stored in a way the compiler can "see" its unicity, and not
typed more than once.
Ditto.
