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std::chrono::day::operator++, std::chrono::day::operator--

From cppreference.com
< cpp‎ | chrono‎ | day
 
 
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C-style date and time
 
 
constexpr std::chrono::day& operator++() noexcept;
(1) (since C++20)
constexpr std::chrono::day operator++(int) noexcept;
(2) (since C++20)
constexpr std::chrono::day& operator--() noexcept;
(3) (since C++20)
constexpr std::chrono::day operator--(int) noexcept;
(4) (since C++20)

Adds or subtracts 1 from the day value.

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

Contents

[edit] Parameters

(none)

[edit] Return value

1,3) a reference to this day after modification
2,4) a copy of the day made before modification

[edit] Notes

If the result would be outside the range [0, 255], the actual stored value is unspecified.

[edit] Example

#include <iostream>
#include <chrono>
 
int main()
{
 
    std::chrono::day d {15};
 
    ++d;
    if (d == std::chrono::day(16)) {
        std::cout << "Day incremented correctly" << "\n";
    } else {
        std::cout << "Day not incremented correctly" << "\n";
    }
 
    --d;
    if (d == std::chrono::day(15)) {
        std::cout << "Day decremented correctly" << "\n";
    } else {
        std::cout << "Day not decremented correctly" << "\n";
    }
 
}

Output:

Day incremented correctly
Day decremented correctly

[edit] See also

adds or subtracts a number of days
(public member function) [edit]
adds or subtracts a number of days and a day, or find the difference between two days
(function) [edit]