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digitalmars.D.learn - How to use std.bind?

reply Sean Eskapp <eatingstaples gmail.com> writes:
I used to use boost::bind all the time, but std.bind has me stumped, as I keep
getting static asserts with a cryptic "argument has no parameters" message. At
this point, the code is just:

class Foo
{
	void bar(int i) { writeln(i); }
}

void main()
{
	auto foobar = new Foo;
	bind(&foobar.bar, 5)();
}

I've tried a myriad of different ways, but keep coming up with the same error.
Using bindAlias gives me an error that "std.bind.bindAlias(alias FT) is not a
function template.

I'm using DMD v2.051 on a Windows platform. Help anybody?
Jan 17 2011
next sibling parent BlazingWhitester <max.klyga gmail.com> writes:
On 2011-01-17 19:03:15 +0200, Sean Eskapp said:


 I used to use boost::bind all the time, but std.bind has me stumped, as I keep
 getting static asserts with a cryptic "argument has no parameters" message. At
 this point, the code is just:
 
 class Foo
 {
 	void bar(int i) { writeln(i); }
 }
 
 void main()
 {
 	auto foobar = new Foo;
 	bind(&foobar.bar, 5)();
 }
 
 I've tried a myriad of different ways, but keep coming up with the same error.
 Using bindAlias gives me an error that "std.bind.bindAlias(alias FT) is not a
 function template.
 
 I'm using DMD v2.051 on a Windows platform. Help anybody?


std.bind is scheduled for deprecation, use lambda-expressions instead
Jan 17 2011
prev sibling parent reply "Lars T. Kyllingstad" <public kyllingen.NOSPAMnet> writes:
On Mon, 17 Jan 2011 17:03:15 +0000, Sean Eskapp wrote:


 I used to use boost::bind all the time, but std.bind has me stumped, as
 I keep getting static asserts with a cryptic "argument has no
 parameters" message. At this point, the code is just:
 
 class Foo
 {
 	void bar(int i) { writeln(i); }
 }
 
 void main()
 {
 	auto foobar = new Foo;
 	bind(&foobar.bar, 5)();
 }
 
 I've tried a myriad of different ways, but keep coming up with the same
 error. Using bindAlias gives me an error that "std.bind.bindAlias(alias
 FT) is not a function template.
 
 I'm using DMD v2.051 on a Windows platform. Help anybody?


Like BlazingWhitester said, std.bind is scheduled for deprecation.  (It 
will be marked as such starting with the next DMD release.)  It is a 
relic from D1, and I don't think it has worked well with D2 for quite a 
while.

Luckily, you don't need it at all.  You can do the same thing with D2's 
built-in features, such as nested functions and lambdas.

  // Lambda example
  int add2(int i) { return i + 2; }

  void main()
  {
      auto seven = () { return add2(5); };
      assert (seven() == 7);
  }

-Lars
Jan 18 2011
parent Andrej Mitrovic <andrej.mitrovich gmail.com> writes:
On 1/18/11, Lars T. Kyllingstad <public kyllingen.nospamnet> wrote:

 On Mon, 17 Jan 2011 17:03:15 +0000, Sean Eskapp wrote:


 I used to use boost::bind all the time, but std.bind has me stumped, as
 I keep getting static asserts with a cryptic "argument has no
 parameters" message. At this point, the code is just:

 class Foo
 {
 	void bar(int i) { writeln(i); }
 }

 void main()
 {
 	auto foobar = new Foo;
 	bind(&foobar.bar, 5)();
 }

 I've tried a myriad of different ways, but keep coming up with the same
 error. Using bindAlias gives me an error that "std.bind.bindAlias(alias
 FT) is not a function template.

 I'm using DMD v2.051 on a Windows platform. Help anybody?


 Like BlazingWhitester said, std.bind is scheduled for deprecation.  (It
 will be marked as such starting with the next DMD release.)  It is a
 relic from D1, and I don't think it has worked well with D2 for quite a
 while.

 Luckily, you don't need it at all.  You can do the same thing with D2's
 built-in features, such as nested functions and lambdas.

   // Lambda example
   int add2(int i) { return i + 2; }

   void main()
   {
       auto seven = () { return add2(5); };
       assert (seven() == 7);
   }

 -Lars


This is better:
http://www.digitalmars.com/d/2.0/phobos/std_functional.html#curry
Jan 18 2011