Michel Fortin wrote:
On 2010-12-10 17:12:16 -0500, Don <nos...@nospam.com> said:

Steven Schveighoffer wrote:
To summarize for those looking for the C++ behavior, the equivalent would be:

void foo(auto ref const Widget)

That use of 'auto' is an abomination.

One problem I'm starting to realize is that we now have so many available qualifiers for function parameters than it's really easy to get lost.

In D1 it was simple: "in" for regular arguments (the default), "inout"/"ref" for passing arguments by refrence, and "out" for output arguments. They all had clear semantics and not too much overlap.

In D2, we've lost this simplicity. Add "const/immutable/shared", add "scope", change "in" as an alias for "const scope", give "inout" a totally new meaning, keep "ref" and "out" the same except that now "ref" can be prefixed with "auto" to give it a double meaning... choosing the right modifiers for function parameters is getting extra complicated.

Have we lost track of one of D's principles, that doing the right thing should be the easiest way to do things? To me it looks like we're adding more and more ways to pass arguments because the defaults are failing us. Perhaps it's time to revisit how arguments are passed by default.

As for "auto ref", if we're to keep it I think it'd be much better if it was a keyword of its own, such as "autoref". Having modifiers is one thing, but having modifiers that apply to modifiers is getting a little hard to parse in my head.

> This is not unprecedented, in English when one
qualifier apply to another and it becomes hard to read we group them by adding a hyphen between the two.

The problem is that 'auto' in 'auto ref' has *a contradictory meaning* to every other usage of 'auto' in the language.

If we need another keyword, we have to create another keyword.
Almost any other syntax would be better.

And as far as I can tell, 'auto ref', 'scope' and 'in' as function parameters aren't explained at all in the spec.

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