2708. recursive_directory_iterator::recursion_pending() is incorrectly specified

Section: 30.11.13.1 [fs.rec.dir.itr.members] Status: Open Submitter: Eric Fiselier Opened: 2016-05-09 Last modified: 2017-03-19

Priority: 2

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Discussion:

The current specification of recursion_pending() says (30.11.13.1 [fs.rec.dir.itr.members]/24):

Returns: true if disable_recursion_pending() has not been called subsequent to the prior construction or increment operation, otherwise false.

This language does not take into account cases where the prior construction was a copy construction from a iterator, it, where it.recursion_pending() == false.

[2016-08 Chicago]

Wed AM: Move to Open

Proposed resolution:

This wording is relative to N4582.

  1. Change 30.11.13.1 [fs.rec.dir.itr.members] as indicated:

    explicit recursive_directory_iterator(const path& p);
    recursive_directory_iterator(const path& p, directory_options options);
    recursive_directory_iterator(const path& p, directory_options options, error_code& ec) noexcept;
    recursive_directory_iterator(const path& p, error_code& ec) noexcept;
    

    […]

    -3- Postcondition: options() == options for the signatures with a directory_options argument, otherwise options() == directory_options::none.

    • options() == options for the signatures with a directory_options argument, otherwise options() == directory_options::none.

    • recursion_pending() == true.

    […]

    [Drafting note: The following changes the specification of recursion_pending() seemingly recursive. Perhaps it would be easier to specify recursion_pending() in terms of a exposition only member in recursive_directory_iterator.]

    bool recursion_pending() const;
    

    […]

    -24- Returns: true if disable_recursion_pending() has not been called subsequent to the prior construction or increment operation, otherwise falsefalse if disable_recursion_pending() has been called subsequent to the prior construction or increment operation, otherwise the value of recursion_pending() set by that operation.

    […]

    recursive_directory_iterator& operator++();
    recursive_directory_iterator& increment(error_code& ec) noexcept;
    

    […]

    -27- Effects: As specified by Input iterators (24.2.3), except that: […]

    -?- Postcondition: recursion_pending() == true.