On 06/23/2013 12:19 PM, Artur Skawina wrote:
On 06/22/13 21:52, Timothee Cour wrote:
Is there a reason the language spec disallows this?
----
void main(){
auto a=mixin("1");//OK
alias b=a;//OK
mixin("alias c=a;");//OK
// alias c=mixin("a");//NG : Error: basic type expected, not mixin
}
How would that be different from "auto c=mixin("a");"?
It's probably clear, but that error message is misleading, so i'll say
it anyway - the reason why your 'alias' line does not work is because
alias requires a symbol, but 'mixin()' is an expression.
Special-casing mixin-expressions (so that they propagate the symbol when
that is possible would be a bad idea); the other possibility is to allow
aliasing /expressions/. But that's a bad idea too, and would likely not
do what you expect it to do. A mixin-less version could be made to work,
but there are already other ways to get the same effect.
Hence the above question.
artur
mixin template T(alias x){ }
void foo(){ import std.stdio; writeln("foo"); }
void main(){
auto a=mixin("1");
mixin T!a; // ok
mixin T!(mixin("a")); // ok
mixin T!1; // ok (!)
mixin T!(mixin("foo")); // ok (no implicit call)
}
