std::chrono::year_month_day_last::operator+=, std::chrono::year_month_day_last::operator-=

From cppreference.com

 
C++
 
Utilities library
Type support (basic types, RTTI, type traits)
Dynamic memory management
Error handling
Program utilities
Variadic functions
Library feature-test macros
Date and time
Function objects
(C++11)
(C++11)
(C++14)
Relational operators (deprecated in C++20)
Comparisons (C++20)
Common vocabulary types
(C++11)
(C++17)
(C++17)
(C++17)
(C++17)
(C++17)

Swap, forward and move
(C++14)
(C++11)
(C++11)
(C++11)
Elementary string conversions
(C++17)
(C++17)
(C++17)
Type operations
(C++11)
(C++17)
(C++17)
 
Date and time utilities
(C++11)
(C++11)
(C++20)
Clocks
(C++11)
(C++11)
(C++11)
(C++20)
                                                  
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
Calendars
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
Time zones
(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-style date and time
 
std::chrono::year_month_day_last
 
constexpr std::chrono::year_month_day_last& operator+=(const std::chrono::years& dy) const noexcept;
 (1) (since C++20)
constexpr std::chrono::year_month_day_last& operator+=(const std::chrono::months& dm) const noexcept;
 (2) (since C++20)
constexpr std::chrono::year_month_day_last& operator-=(const std::chrono::years& dy) const noexcept;
 (3) (since C++20)
constexpr std::chrono::year_month_day_last& operator-=(const std::chrono::months& dm) const noexcept;
 (4) (since C++20)

Modifies the time point *this represents by the duration dy or dm.

1) Equivalent to *this = *this + dy;
2) Equivalent to *this = *this + dm;
3) Equivalent to *this = *this - dy;
4) Equivalent to *this = *this - dm;

Notes

Durations that are convertible to std::chrono::months, but not std::chrono::years, can be directly added to or subtracted from a year_month_day_last. Durations convertible to std::chrono::years cannot because such durations are also convertible to std::chrono::months, resulting in an ambiguity: 

using namespace std::chrono;
 
using decades = duration<int, std::ratio_multiply<std::ratio<10>, years::period>>;
using kilomonths = duration<int, std::ratio_multiply<std::kilo, months::period>>;
 
auto ymdl = 2001y/April/last;
ymdl += decades{1}; // error, ambiguous
ymdl += kilomonths{1}; // OK

See also

adds or subtracts a year_month_day_last and some number of years or months
(public member function)
Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/chrono/year_month_day_last/operator_arith&oldid=104810"