DIP1000: Walter's proposal to resolve ambiguity of ref-return-scope parameters

[Paul Backus]

On Friday, 26 November 2021 at 01:48:28 UTC, zjh wrote:
> On Thursday, 25 November 2021 at 22:36:38 UTC, Walter Bright 
> wrote:
>
>> I've suggested removing `lazy` already, with the predicted 
>> response.
>
> `lazy` can be deleted completely. One can replace it with 
> something similar to the `concept` of C++.

There's one use of `lazy` that can't be easily replaced, which is 
template functions like [`std.exception.ifThrown`][1]. Without 
`lazy`, we would have to rewrite code like this

```d
auto result = doStuff(x, y, z).ifThrown(w);
```

...to look like this:

```d
auto result = (() => doStuff(x, y, z)).ifThrown(w);
```

Personally I don't think this is a huge deal--`lazy` is not very 
commonly used in the first place, and having to write a few extra 
characters in the places where it is used is not a terrible 
imposition. But it is still a breaking change.

[1]: https://phobos.dpldocs.info/std.exception.ifThrown.1.html