Re: [Boost-users] calling a member function of a map iterator

From: Alexander Shyrokov (shirokov_at_[hidden])
Date: 2006-09-15 17:51:35

> In such a situation I tend to define my own nullptr:
> 
> struct nullptr_t
> {
>     template<class T> operator T* () const { return 0; }
> } nullptr;
> 
> and use that instead of NULL. 
Thanks, Peter. Both casting and nullptr worked fine. But it brings me to 
a bigger question, should I bother replacing this code:

struct c{void f(char*){}};
typedef std::map<int,c*> TMap;
TMap a;
for(TMap::iterator i=a.begin();i!=a.end();++i)(*a)->second.f(NULL):

with the more complex code like this:

struct c{void f(char*){}};
struct nullptr_t{template<class T>operator T*()const{return 0;}}nullptr;
typedef std::map<int,c*> TMap;
TMap a;
std::for_each(a.begin(),a.end(),
        boost::bind(&c::f,
                boost::bind(&TMap::value_type::second,_1),
                nullptr)
        );

I know there should be a line. But I am new to the algorithm's way :)
Thanks.

-- 
Regards,
     Alexander.                http://sjcomp.com