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digitalmars.D - `lvalueof` property on rvalues

reply Basile B. <b2.temp gmx.com> writes:
what about

```d
void fun(ref int);
fun(1.lvalueof);
```

previous work : https://wiki.dlang.org/DIP39

The `lvalueof` property could create a temporary variable if the 
exp it's used on is not already a lvalue, otherwise it would do 
nothing.
May 09 2022
parent reply Bastiaan Veelo <Bastiaan Veelo.net> writes:
On Monday, 9 May 2022 at 14:03:21 UTC, Basile B. wrote:

 [...] create a temporary variable if the exp it's used on is 
 not already a lvalue, otherwise it would do nothing.


That's what happens if you supply the `-preview=rvaluerefparam` 
compiler argument, right? Then this already works:

```d
void fun(ref int i) {}

void main()
{
     fun(1);
}
```

There is also `-preview=in`.

So what is the advantage of having to add `.lvalueof`?

-- Bastiaan.
May 12 2022
parent Basile B. <b2.temp gmx.com> writes:
On Thursday, 12 May 2022 at 08:06:14 UTC, Bastiaan Veelo wrote:

 On Monday, 9 May 2022 at 14:03:21 UTC, Basile B. wrote:

 [...] create a temporary variable if the exp it's used on is 
 not already a lvalue, otherwise it would do nothing.


 That's what happens if you supply the `-preview=rvaluerefparam` 
 compiler argument, right? Then this already works:

 ```d
 void fun(ref int i) {}

 void main()
 {
     fun(1);
 }
 ```

 There is also `-preview=in`.

 So what is the advantage of having to add `.lvalueof`?

 -- Bastiaan.


Ok, I was not aware of that. It's would be indeed useless if D 
can already do that implictly.
May 12 2022