This isn't my desired answer, but thank you for your answer, however.
----- Original Message -----
From: Oliver Seiler
Newsgroups: gmane.comp.lib.boost.user
To: boost-users@lists.boost.org
Sent: Thursday, June 05, 2008 4:12 AM
Subject: Re: A question about boost::bind function

Not sure why this was changed, though I've never used bind in this way (specifically, to bind to a reference of a member variable).

Are you free to make changes to the code? This should work in either version:

void AddUserAge( _sUserData& d ) { // <-- change this to a reference to the struct
   
++
d.age;
}

int _tmain(int argc, _TCHAR*
argv[])
{
    std::vector
<_sUserData>
vUserData;
   
for( int i = 0; i < 10; ++
i )
        vUserData.push_back( _sUserData() );
    std::for_each( vUserData.begin(), vUserData.end(), boost::bind( AddUserAge, _1 )); // <-- and remove the inner bind

   
return 0
;
}


Or you could just do this in 1.34.0 or higher:

#include <boost/foreach.hpp>
....
int _tmain(int argc, _TCHAR* argv[]) {
    std::vector
<_sUserData>
vUserData( 10 ); // vector of 10 _sUserData, default constructed
    BOOST_FOREACH(
_sUserData& d, vUserData ) ++d.age;
    return 0;
}


Of course, all this is starting to look like a homework problem to me...

2008/6/3 风舞影天 <snwcwt@qq.com>:
I'm a newbie in boost library and sorry for my poor English.
 
I have a project now, it was created in Visual Studio.Net 2003 and the version of the boost library is 1.33.1, all thing is good. But, When I replaced the boost library with the new version 1.34.1 or 1.35.0,  the project can't compiled correct. The error message is 'can't convert const sometype& to sometype&'.  So, i force myself to read the source code of boost library and compare them betwwen version 1.33.1 and version 1.44.1. at last, I found the problem and written a test program. The following code is the test program:
 
#include "stdafx.h"
#include <boost/bind.hpp>
#include
<vector>
#include
<algorithm>

struct _sUserData
{
   
int
        m_nUserId;
   
int
        m_nUserAge;
    _sUserData()
        : m_nUserId( rand() )
        , m_nUserAge( rand()
%100+1
)
    {
    }
};

void AddUserAge( int&
age )
{
   
++
age;
}

int _tmain(int argc, _TCHAR*
argv[])
{
    std::vector
<_sUserData>
vUserData;
   
for( int i = 0; i < 10; ++
i )
        vUserData.push_back( _sUserData() );
    std::for_each( vUserData.begin(), vUserData.end(), boost::bind( AddUserAge, boost::bind(
&
_sUserData::m_nUserAge, _1 ) ) );
   
return 0
;
}

If i change the function AddUserAge( int& age ) to AddUserAge( const int& age ), all things is good. but I need change this parameter.



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