Document number: P1982R0

Howard E. Hinnant
2019-11-09

Rename link to time_zone_link

Introduction
Wording

Introduction

The LEWG in Belfast requested that I write a paper which provides wording for DE 346 as modified by the discussion in LEWG. The LEWG chose the name time_zone_link as a replacement for link, and specifically chose not to change the associated data member of tzdb links.

Wording

Modify the synopsis in [time.syn] as indicated:

...
// 27.11.9, class link
class link;

bool operator==(const link& x, const link& y);
strong_ordering operator<=>(const link& x, const link& y);
...

Modify the synopsis in [time.zone.db.tzdb] as indicated:

namespace std::chrono {
  struct tzdb {
    string                 version;
    vector<time_zone>      zones;
    vector<link> links;
    vector<leap>           leaps;

    const time_zone* locate_zone(string_view tz_name) const;
    const time_zone* current_zone() const;
  };
}

Modify [time.zone.db.tzdb]/p2 as indicated:
```
const time_zone* locate_zone(string_view tz_name) const;
```
2 Returns: If a time_zone is found for which name() == tz_name, returns a pointer to that time_zone. Otherwise if a link is found for which tz_name == link.name(), then a pointer is returned to the time_zone for which zone.name() == link.target().
[Note: A link specifies an alternative name for a time_zone. — end note]
Modify the title of [time.zone.link] as indicated:

Class link

Modify [time.zone.link.overview] as indicated:

namespace std::chrono {
  class link {
  public:
    link(link&&) = default;
    link& operator=(link&&) = default;

    // unspecified additional constructors

    string_view name()   const noexcept;
    string_view target() const noexcept;
  };
}

1 A link specifies an alternative name for a time_zone. links are constructed when the time zone database is initialized.

Modify [time.zone.link.members]/p2 as indicated:
```
string_view target() const noexcept;
```
2 Returns: The name of the time_zone for which this link provides an alternative name.

Modify [time.zone.link.nonmembers] as indicated:

bool operator==(const link& x, const link& y) noexcept;
1 Returns: x.name() == y.name().
strong_ordering operator<=>(const link& x, const link& y) noexcept;
2 Returns: x.name() <=> y.name().

Rename link to time_zone_link

Contents

Introduction

Wording