Proposed resolution:

This resolution is relative to N4687.

1. Edit [mem.res.pool.mem] as indicated:

   bool synchronized_pool_resource::do_is_equal(const memory_resource& other) const noexcept override;
       const memory_resource& other) const noexcept override;
   

   Returns: this == dynamic_cast<const synchronized_pool_resource*>(&other).

2. Strike [mem.res.pool.mem] paragraph 10, and the immediately preceding declaration of unsynchronized_pool_resource::do_is_equal.

3. Edit [mem.res.monotonic.buffer.mem] as indicated:

   bool do_is_equal(const memory_resource& other) const noexcept override;
   

   Returns: this == dynamic_cast<const monotonic_buffer_resource*>(&other).

[ 2018-3-17 Adopted in Jacksonville ]

[ 2017-11-01 Moved to Tentatively Ready after 7 positive votes for P0 on c++std-lib. ]

[ 2017-09-18, Casey Carter expands PR to cover the pool resources. ]

1. Edit [mem.res.monotonic.buffer.mem] as indicated:

   bool do_is_equal(const memory_resource& other) const noexcept override;
   

   Returns: this == dynamic_cast<const monotonic_buffer_resource*>(&other).

[ 2017-07-16, Tim Song comments ]

The pool resource classes appear to also have this issue.

Section [mem.res.monotonic.buffer.mem], paragraph 11 says

bool do_is_equal(const memory_resource& other) const noexcept override;

Returns: this == dynamic_cast<const monotonic_buffer_resource*>(&other).

The dynamic_cast adds nothing of value. It is an incorrect cut-and-paste from an example do_is_equal for a more complex resource.