Здравствуйте, st0nx


S> if(std::find_if(cookie.begin(),cookie.end(),(boost::bind(&HttpSendRecv_boost::findvector,_1,_2,_3,buf))) == cookie.end())
S> {
S> cookie.push_back(buf);
S> }

Попробуйте так:

if(std::find_if(cookie.begin(),cookie.end(),(boost::bind(&HttpSendRecv_boost::findvector,this,buf,_1))) == cookie.end())
{
cookie.push_back(buf);
}