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std::chrono::month::operator++, std::chrono::month::operator--

From cppreference.com
< cpp‎ | chrono‎ | month
 
 
Date and time library
(C++11)
(C++20)
(C++11)
(C++11)
(C++11)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)(C++20)
(C++20)(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)(C++20)
(C++20)

 
 
constexpr std::chrono::month & operator++() noexcept;
(1) (since C++20)
constexpr std::chrono::month operator++( int ) noexcept;
(2) (since C++20)
constexpr std::chrono::month & operator--() noexcept;
(3) (since C++20)
constexpr std::chrono::month operator--( int ) noexcept;
(4) (since C++20)

Adds or subtracts 1 from the month value, reducing the result modulo 12 to an integer in the range [112].

1,2) Performs *this += std::chrono::months {1};.
3,4) Performs *this -= std::chrono::months {1};.

[edit] Parameters

(none)

[edit] Return value

1,3) A reference to this month after modification.
2,4) A copy of the month made before modification.

[edit] Notes

After a call to one of these functions, ok() is always true.

[edit] Example

Run this code
#include <cassert>
#include <chrono>
#include <iostream>
 
int main()
{
 std::chrono::month m{6};
 
 ++m;
 assert (m == std::chrono::month (7));
 
 --m;
 assert (m == std::chrono::month (6));
 
 m = std::chrono::December ;
 m++; // rounds up to January
 assert (m.ok());
 std::cout << unsigned(m) << '\n';
 
 m = std::chrono::January ;
 m--; // rounds down to December
 assert (m.ok());
 std::cout << unsigned(m) << '\n';
}

Output:

1
12

[edit] See also

adds or subtracts a number of months
(public member function) [edit]
performs arithmetic on months
(function) [edit]
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