Re: Template: given: the method, searched: the class

From:

Greg Herlihy <gregh@podbridge.com>

Newsgroups:

comp.lang.c++.moderated

Date:

Wed, 10 Oct 2007 05:01:26 CST

Message-ID:

<C331AC75.8E1%gregh@podbridge.com>

On 10/8/07 10:12 AM, in article
1191849784.009751.112030@g4g2000hsf.googlegroups.com,
"t.lehmann@rtsgroup.net" <t.lehmann@rtsgroup.net> wrote:

see following code example (working mechanism):
- - -
struct X{ void test(bool); };
std::for_each(xcont.begin(), xcont.end(), use_method<X>(&X::test,
true));
- - -

Is it possible to write the 'use_method' like this:
- - -
std::for_each(cont.begin(), cont.end(), use_method(&X::test, true));
- - -

How do I get the class from the method?
(If possible - I guess with template specialization - but how?)

Actually, the for_each loop described above can be implemented using only
classes from the current (2003) C++ Standard library. No TR1, boost or
homemade template classes are needed here:

    #include <functional>
    #include <vector>
    #include <algorithm>

    using std::for_each;
    using std::bind2nd;
    using std::mem_fun_ref;

    struct X
    {
        void test(bool b) { }
    };

    int main()
    {
        std::vector<X> cont;

        ...
        for_each( cont.begin(), cont.end(),
                    bind2nd( mem_fun_ref( &X::test), true));
    }

Greg

--
      [ See http://www.gotw.ca/resources/clcm.htm for info about ]
      [ comp.lang.c++.moderated. First time posters: Do this! ]