pointer to member without 'this' - mem_fun like

[Vlad]

Derek Parnell wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> On Tue, 18 Mar 2008 11:27:23 +0200, Vlad wrote:
> 
>> Hi list,
>>
>> I was wondering if D has something like C's mem_fun, where one can pass 
>> a pointer to a member function of a class, that later can be called with 
>> various 'this' instances.
> 
> Excuse my ignorance, but what is the benefit of this technique?
> 
 > - --
 > Derek Parnell

Example: writing a map()-like function that works on a collection of 
objects and calling a method on them, instead of a free function



Pseudocode:
(with a 'free function'):

string in[] = ...
int out[] = map (in, len);

(with a 'member_fun'):
T in[] = ...
T out[] = map(in, &T.do_something);

or even:
T in[] = ...
int out[] = map(in, &T.get_some_int_property)