Re: Delegates: Print 0..9

[Timon Gehr via Digitalmars-d-learn]

On 01.12.2016 21:12, Ali Çehreli wrote:


This is a common issue with D and some other languages (as I had learned
during a Dart language presentation, of which Dart does not suffer
from). All those delegates do close on the same loop variable. You need
to produce copies of the variable.

This is a common misconception. It's an implementation bug. The 
variables /are/ distinct. It is actually memory corruption. Evidence:

import std.stdio;

void main(){
    int delegate()[] dgs;
    foreach(immutable i;0..10){
        dgs~=()=>i; // i is immutable
    }
    foreach(dg;dgs) writeln(dg()); // yet changes
    dgs=[];
    foreach(i;0..10){
        int j=i; // creating a new variable
        dgs~=()=>j;
    }
    foreach(dg;dgs) writeln(dg()); // does not help
}