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

Since C++20

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

# Declarations

constexpr std::chrono::month& operator++() noexcept;

(since C++20)

constexpr std::chrono::month operator++( int ) noexcept;

(since C++20)

constexpr std::chrono::month& operator--() noexcept;

(since C++20)

constexpr std::chrono::month operator--( int ) noexcept;

(since C++20)

# Notes

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

# Example

#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';
}

# See also