2724. The protected virtual member functions of memory_resource should be private

Section: 20.4.2 [mem.res.class] Status: C++17 Submitter: Ville Voutilainen Opened: 2016-06-04 Last modified: 2017-07-30

Priority: 4

View all other issues in [mem.res.class].

View all issues with C++17 status.

Discussion:

memory_resource doesn't define any behavior, it's just an interface. Furthermore, we don't say whether the functions at [memory.resource.prot] should or should not be defined by implementations. Presumably they should not. Those functions are not designed to be called by derived classes, and thus should not be protected.

[2016-06 Oulu]

Looks fine, check with Pablo to make sure that was his intent.

Pablo replied that this was correct.

Friday: status to Immediate

Proposed resolution:

This wording is relative to N4582.

1. Modify [memory.resource.class] as indicated:

   class memory_resource {
     […]
   protectedprivate:
     virtual void* do_allocate(size_t bytes, size_t alignment) = 0;
     virtual void do_deallocate(void* p, size_t bytes, size_t alignment) = 0;
     virtual bool do_is_equal(const memory_resource& other) const noexcept = 0;
   };
   

2. Modify [memory.resource.prot] as indicated:

   [Drafting note: I don't know whether it's too late to change the section mnemonic [memory.resource.prot] to e.g. [memory.resource.priv] or perhaps [memory.resource.virt].]

   memory_resource protectedprivate virtual member functions [memory.resource.prot]