std::chrono::month::operator++, std::chrono::month::operator--
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std::chrono::month 
 
 
 Member functions
month::operator++month::operator--
 Nonmember functions
 Helper classes
(C++26)
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 [1, 12].
1,2) Performs *this += std::chrono::months {1};.
3,4) Performs *this -= std::chrono::months {1};.
Contents
[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