Returning value by ref does not create a ref. Is this intentional?
Stanislav Blinov
stanislav.blinov at gmail.com
Wed Jan 5 05:17:10 UTC 2022
On Wednesday, 5 January 2022 at 04:35:12 UTC, Tejas wrote:
> ```d
> import std.stdio:writeln;
>
> ref int func(return ref int a){
> a = 6; // modifies a as expected
> return a;
> }
> void main(){
> int a = 5;
> auto c = func(a); // I expected c to alias a here
> c = 10; // Expected to modify a as well
> writeln(a); // prints 6 :(
> }
> ```
>
> The [spec](https://dlang.org/spec/function.html#ref-functions)
> states:
>
>> Ref functions allow functions to return by reference, meaning
>> that the return value must be an lvalue, and the lvalue is
>> returned, not the rvalue.
>
>
>
> Then why does the reference to `a` not get returned ?
It is returned. But initializing `c` with it makes a copy. This
will mutate `a`:
```
func(a) = 10;
```
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