rvalues -> ref (yup... again!)

[Manu]

On 26 March 2018 at 16:21, Rubn via Digitalmars-d
<digitalmars-d at puremagic.com> wrote:
> On Monday, 26 March 2018 at 22:48:38 UTC, Walter Bright wrote:
>>
>> On 3/26/2018 12:24 PM, Manu wrote:
>>>
>>> On 26 March 2018 at 07:40, Atila Neves via Digitalmars-d
>>>>
>>>> C++ const T& -> D T
>>>
>>>
>>> Yeah, no... T may be big. Copying a large thing sucks. Memory copying
>>> is the slowest thing computers can do.
>>> As an API author, exactly as in C++, you will make a judgement on a
>>> case-by-case basis on this matter. It may be by-value, it may be by
>>> const-ref. It depends on a bunch of things, and they are points for
>>> consideration by the API author, not the user.
>>
>>
>> Copying does suck, I agree. Consider the following:
>>
>>     void foo(T t) { foo(t); } <= add this overload
>>     void foo(ref T t) { ... }
>>     T aaa();
>>
>>     foo(aaa());
>>
>> With inlining, I suspect we can get the compiler to not make any extra
>> copies. It's not that different from NRVO. And as a marvy bonus, no weird
>> semantic problems (as Atila mentioned).
>
>
> How do you add this overload for the following?
>
>
> void foo(ref T t) { ... }
>
> void function(ref int) func = &foo;
> int aaa();
>
> func(aaa()); // err

Exactly.