Delegates and values captured inside loops
An Pham
home at home.com
Sun Jan 21 23:58:08 UTC 2024
On Sunday, 21 January 2024 at 20:13:38 UTC, An Pham wrote:
> On Saturday, 20 January 2024 at 15:59:59 UTC, Anonymouse wrote:
>> I remember reading this was an issue and now I ran into it
>> myself.
>>
>> ```d
>> import std.stdio;
>>
>> void main()
>> {
>> auto names = [ "foo", "bar", "baz" ];
>> void delegate()[] dgs;
>>
>> foreach (name; names)
>> {
>> dgs ~= () => writeln(name);
>> }
>>
>> foreach (dg; dgs)
>> {
>> dg();
>> }
>> }
>> ```
>>
>> Expected output: `foo`, `bar`, `baz`
>> Actual output: `baz`, `baz`, `baz`
>>
>
For c# reference when they fixed it:
https://stackoverflow.com/questions/3168375/using-the-iterator-variable-of-foreach-loop-in-a-lambda-expression-why-fails
To have a way out for old behavior by capture reference,
from: dgs ~= () => writeln(name);
to: dgs ~= () => writeln(&name);
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