Re: Whitch can replace std::bind/boost::bind ?

[Dsby via Digitalmars-d-learn]

On Friday, 18 March 2016 at 17:24:27 UTC, Ali Çehreli wrote:
On 03/18/2016 03:50 AM, Dsby wrote:

foreach (i ; 0..4) {
     auto th = new Thread(delegate(){listRun(i);});//this is 
erro
     _thread[i]= th;
     th.start();
}

void listRun(int i)
{
      writeln("i = ", i); // the value is not(0,1,2,3), it all 
is 2.
}


I want to know how to use it like std::bind.



A workaround is an intermediate function that returns the 
delegate:

import std.stdio;
import core.thread;

void listRun(int i)
{
     writeln("i = ", i); // the value is not(0,1,2,3), it all 
is 2.
}

auto makeClosure(int i) {
    return delegate(){listRun(i);};
}

void main() {
    Thread[4] _thread;

    foreach (i ; 0..4) {
        auto th = new Thread(makeClosure(i));
        _thread[i]= th;
        th.start();
    }
}

Prints different values:

i = 1
i = 0
i = 2
i = 3

Ali

Thanks for your mind.
i write the bind function:

import std.stdio;
import core.thread;
import std.functional;

class AA
{
    void show(int i)
    {
        writeln("i = ", i); // the value is not(0,1,2,3), it all 
is 2.
    }

}


void listRun(int i)
{
     writeln("i = ", i);
}


void main() {
    Thread[4] _thread;
    Thread[4] _thread2;
     AA a = new AA();
    foreach (i ; 0..4) {
        auto th = new Thread(bindDg(&a.show,i));
        _thread[i]= th;
        auto th2 = new Thread(bindFun!listRun(i + 10));
        _thread2[i]= th2;
    }

    foreach(i;0..4)
    {
        _thread[i].start();
    }

    foreach(i;0..4)
    {
        _thread2[i].start();
    }

}


auto bindDg(T, Args...)(T fun,Args args) if (is(T == delegate) || 
is(T == function))
{
        return delegate(){return fun(forward!args);};
}

auto bindFun(alias Fun,Args...)(Args args) {
        return delegate(){return Fun(forward!args);};
}


my value  is :
i = 2
i = 0
i = 3
i = 11
i = 13
i = 10
i = 12
i = 1