On Thursday, 11 June 2015 at 15:03:39 UTC, Dicebot wrote:
Those are considerably less powerful:
- can only have type arguments
- no variadic argument list support
- no arbitrary condition constraints (thus only partial duck
typing support)
On the other hand they have one important advantage: all type
arguments must comply to one or more trairs and thus bodies of
generics are checked before institation. You are only allowed
to call methods and operations of generic arguments that are
defined in relevan trait. This is huge win for code hygiene
compared to D.
Any sort of more advanced meta-programming things can only be
done via AST macros which is currently the biggest downside in
my eyes when it comes to features. Though quite some people
like that.
The fact that there is no support variadiŃ arguments, it is
really negative.
It is possible that Walter and Andrei against macro because of
this:
macro_rules! o_O {
(
$(
$x:expr; [ $( $y:expr ),* ]
);*
) => {
&[ $($( $x + $y ),*),* ]
}
}
fn main() {
let a: &[i32]
= o_O!(10; [1, 2, 3];
20; [4, 5, 6]);
assert_eq!(a, [11, 12, 13, 24, 25, 26]);
}
It looks disgusting! ;)
