pointer that propagates it's modifiers to the value

[Alexey Mamontov]

The idea is simple. I need to have some member by pointer (using the abstract base class, for example), but I want it to behave absolutely the same as member by value - it must inherit the constantness of this.

Lets call it member_ptr<T> and see what I mean:

T * member_ptr<T>::operator->();

const T * member_ptr<T>::operator->() const;

T & member_ptr<T>::operator*();

const T & member_ptr<T>::operator*() const;

struct B

{

 void f() = 0;

 void f() const = 0;

};

struct S

{

 member_ptr<B> m;

};

S s;

s.m->f(); // void f() is called

const S cs;

cs.m->f(); // void f() const is called

All other modifiers (volatile, rvalue) must be forwarded as well... 

[Shahms King]

http://en.cppreference.com/w/cpp/experimental/propagate_const

--Shahms

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[Jonathan Coe]

On 22 Aug 2016, at 20:11, Shahms King <shahm...@gmail.com> wrote:

http://en.cppreference.com/w/cpp/experimental/propagate_const

libc++ and libstd++ both have implementations in trunk.

Please let me know if they don't do what you want.

The libc++ implementation should work pretty easily in VS without significant modification.

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