Re: [boost] mem_var_* (like mem_fun_*)

From: Hamish Mackenzie (boost_at_[hidden])
Date: 2002-01-28 12:30:11

On Mon, 2002-01-28 at 15:13, Hamish Mackenzie wrote:
> I am writing some code that uses a C based API (Microsoft's MAPI) and it
> would be handy to have mem_var_* classes to access members of structures
> without having to write helper functions.  Do these exist already?
> 
> Something like....
> 
> template< Class_Type >

oops should be
template< class Class_Type, class Member_Type >

> class const_mem_var_ref_t : public
>     std::unary_function< Class_Type, Member_Type >
> {
> public:
>   explicit const_mem_var_ref_t( Member_Type Class_Type::* ptr )
>     : ptr_( ptr ) {}
> 
>   const Member_Type &operator()( const Class_Type &x ) const
>   {
>     return x.*ptr_;
>   }
> 
> private:
>   Member_Type Class_Type::* ptr_;
> };
> 
> template< class Class_Type, class Member_Type >
> const_mem_var_ref_t< Class_Type, Member_Type >
>     const_mem_var_ref( Member_Type Class_Type::* ptr )
> {
>   return const_mem_var_ref_t< Class_Type, Member_Type >( ptr );
> }