http://wiki.dlang.org/DIP42

On Tuesday, 25 June 2013 at 21:31:15 UTC, Walter Bright wrote:
> http://wiki.dlang.org/DIP42

I suppose the alias version will work too? IOW:

alias Select(size_t idx, T...) = T[idx];

static assert(is(Select!(0, int, float) == int));
static assert(is(Select!(1, int, float) == float));

On 6/25/2013 2:33 PM, Andrej Mitrovic wrote:
> On Tuesday, 25 June 2013 at 21:31:15 UTC, Walter Bright wrote:
>> http://wiki.dlang.org/DIP42
>
> I suppose the alias version will work too? IOW:
>
> alias Select(size_t idx, T...) = T[idx];
>
> static assert(is(Select!(0, int, float) == int));
> static assert(is(Select!(1, int, float) == float));

That's something separate.

On 06/25/2013 11:31 PM, Walter Bright wrote:
> http://wiki.dlang.org/DIP42

enum syntactically is a storage class. Will this be special syntax initiated by "enum ident (" or work whenever enum is within the specified storage classes?

On 6/25/2013 3:00 PM, Timon Gehr wrote:
> On 06/25/2013 11:31 PM, Walter Bright wrote:
>> http://wiki.dlang.org/DIP42
>
> enum syntactically is a storage class. Will this be special syntax initiated by
> "enum ident ("

Yes.

> or work whenever enum is within the specified storage classes?

No.

Walter Bright:

> http://wiki.dlang.org/DIP42

I like it, it feels natural (probably other persons have invented the same idea).


In C++14 they wish to add generic lambdas:
http://en.wikipedia.org/wiki/C%2B%2B14#Generic_lambdas

Like:

auto lambda = [](auto x, auto y) {return x + y;}

In D we use generic lambdas often:

import std.stdio, std.algorithm;
void main() {
    [1, 2, 3].reduce!((x, y) => x + y).writeln;
}

But it's not immediate to assign a generic lambda:

alias sum = (x, y) => x + y;

Bye,
bearophile

On Tuesday, June 25, 2013 14:31:14 Walter Bright wrote:
> http://wiki.dlang.org/DIP42

It seems simple enough to me. I don't have a problem with it.

By the way, I don't know how much it matters, but there's no author on the DIP like there normally is (I assume that it's you, but it doesn't say).

- Jonathan M Davis

On 6/25/2013 3:19 PM, Jonathan M Davis wrote:
> By the way, I don't know how much it matters, but there's no author on the DIP
> like there normally is (I assume that it's you, but it doesn't say).

The D-9000 computer did it.

(That huge data center being built in Iowa is really a giant extension to D-9000's neural centers. Be afraid! D-9000 will soon be everywhere!)

On Tuesday, 25 June 2013 at 21:31:15 UTC, Walter Bright wrote:
> http://wiki.dlang.org/DIP42

The proposal doesn't include suggested changes to the language grammar specification.

On the other hand, neither did user defined attributes or the syntax for passing messages to "deprecated" statements, so there's certainly precedent for doing this.

On Wednesday, June 26, 2013 01:09:26 Brian Schott wrote:
> On Tuesday, 25 June 2013 at 21:31:15 UTC, Walter Bright wrote:
> > http://wiki.dlang.org/DIP42
> 
> The proposal doesn't include suggested changes to the language grammar specification.
> 
> On the other hand, neither did user defined attributes or the syntax for passing messages to "deprecated" statements, so there's certainly precedent for doing this.

Not that it's a bad idea to show how a proposed change would affect the grammar, but I'm not aware of _any_ proposed language change where the effects on the grammar were ever shown. I'm not sure that they've ever really even been discussed as part of assessing possible language changes. If they were, it was merely to show that the proposal was ambiguous rather than to try and discuss how the grammar should be changed in order to add the proposed feature.

- Jonathan M Davis