On Tuesday, 25 September 2012 at 21:02:49 UTC, Andrei
Alexandrescu wrote:
I agree. That's why I want to take the minimum amount of steps
to make library tuples work. That minimum amount may be 1, i.e.
just implement deconstruction.
Andrei
Library tuples have broken semantics.
Tuples supposed to have _structural_ typing which AFAIK can only
be correctly implemented in language.
import std.typecons.TypeTuple;
struct MyTuple(T...)() {}
auto libTup = tuple(123, "hello");
MyTuple myTup = libTup; // broken
This is broken cause structs in D are nominally typed and even
though both pack the same inner-types, they are not equal.
The problem with the lib solution is the confusion and broken
semantics, _not_ the "tuple()" syntax. Sure, it's long and
annoying to type for a [should be] common construct, but tuple
*is* clear and readable, as you pointed out yourself. So syntax
wise, I'm fine with both tuple(...) and a shorter syntax with
some sort of parens-like character. But please, let's get at
least the semantics absolutely right.
I don't have a good suggestion how to fix this with no or minimal
code breakage, but I don't thing that adding broken features the
the mix helps any.
