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std::chrono::is_am, std::chrono::is_pm, std::chrono::make12, std::chrono::make24

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< cpp‎ | chrono
 
 
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is_amis_pmmake12make24
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C-style date and time
 
Defined in header <chrono>
constexpr bool is_am( const std::chrono::hours& h ) noexcept;
(1) (since C++20)
constexpr bool is_pm( const std::chrono::hours& h ) noexcept;
(2) (since C++20)
constexpr std::chrono::hours make12( const std::chrono::hours& h ) noexcept;
(3) (since C++20)
constexpr std::chrono::hours make24( const std::chrono::hours& h,
                                     bool is_pm ) noexcept;
(4) (since C++20)

These functions aid in translating between a 12-hour format time of day, and a 24-hour format time of day.

1) Detects whether the 24-hour format time is a.m. (ante meridiem, before midday).
2) Detects whether the 24-hour format time is p.m. (post meridiem, after midday).
3) Returns the 12-hour equivalent of a 24-hour format time.
4) Returns the 24-hour equivalent of a 12-hour format time h, where is_pm determines whether the time is p.m.

[edit] Parameters

h - 12-hour or 24-hour format time to detect
is_pm - whether the 12-hour format time is p.m.

[edit] Return value

1) 0h <= h && h <= 11h.
2) 12h <= h && h <= 23h.
3) If h is in range [0h, 23h], returns the 12-hour equivalent in range [1h, 12h]. Otherwise, the return value is unspecified.
4) If h is in range [1h, 12h], returns the 24-hour equivalent in range [0h, 11h] if is_pm is false, or in range [12h, 23h] otherwise. Otherwise, the return value is unspecified.

[edit] Example