Re: Closures over temporary variables

[Ali Çehreli via Digitalmars-d-learn]

On 6/14/22 02:04, bauss wrote:

> You have to do it like this:
>
> ```
> dgs ~= ( (n) => () { writeln(n); })(i);
> ```

The same thing with a named function as well as with iota():

import std.range;
import std.algorithm;
import std.stdio;

void main() {
  void delegate()[] dgs;

  auto makeDg(int i) {
return () => writeln(i);
  }

  foreach (immutable i; 0 .. 3)
  {
dgs ~= makeDg(i);
  }

  iota(3).each!(i => dgs ~= () => writeln(i));

  foreach (dg; dgs)
  {
dg();
  }
}

Ali

Re: Closures over temporary variables

[bauss via Digitalmars-d-learn]

On Tuesday, 14 June 2022 at 08:26:53 UTC, Anonymouse wrote:

What is the correct way of making this output `0 1 2`?

```d
void delegate()[] dgs;

foreach (immutable i; 0..3)
{
dgs ~= () => writeln(i);
}

foreach (dg; dgs)
{
dg();  // outputs: `2 2 2`
}
```


You have to do it like this:

```
dgs ~= ( (n) => () { writeln(n); })(i);
```

Because D hasn't fixed their million dollar mistake after so many 
years:


https://issues.dlang.org/show_bug.cgi?id=2043

https://issues.dlang.org/show_bug.cgi?id=23136

Closures over temporary variables

[Anonymouse via Digitalmars-d-learn]

What is the correct way of making this output `0 1 2`?

```d
void delegate()[] dgs;

foreach (immutable i; 0..3)
{
dgs ~= () => writeln(i);
}

foreach (dg; dgs)
{
dg();  // outputs: `2 2 2`
}
```