std::variant::swap

 

C++

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void swap(variant& rhs)	(1)	(since C++17)

Swaps two variant objects

• if both *this and rhs are valueless by exception, does nothing
• otherwise, if both *this and rhs hold the same alternative, calls swap(std::get<i>(*this), std:get<i>(rhs)) where i is index(). If an exception is thrown, the state of the values depends on the exception safety of the swap function called.
• otherwise, exchanges values of rhs and *this. If an exception is thrown, the state of *this and rhs depends on exception safety of variant's move constructor and move assignment operators.

This overload only participates in overload resolution if std::is_swappable_v<T_i> is true for all T_i in Types...

Parameters

rhs

-

a variant object to swap with

Return value

(none)

Exceptions

May throw any exception thrown by swap(get<i>(*this), get<i>(rhs)) with i being index() and variant's move constructor and move assignment operator.

noexcept specification:  

noexcept((std::is_nothrow_move_constructible_v<Types> && std::is_nothrow_swappable_v<Types>) && ...))