20 General utilities library [utilities]

20.6 Optional objects [optional]

20.6.3 Class template optional [optional.optional]

20.6.3.5 Swap [optional.swap]

Table 49: optional​::​swap(optional&) effects [tab:optional.swap]
*this contains a value
*this does not contain a value
rhs contains a value
calls swap(*(*this), *rhs)
direct-non-list-initializes the contained value of *this with std​::​move(*rhs), followed by rhs.val->T​::​~T(); postcondition is that *this contains a value and rhs does not contain a value
rhs does not contain a value
direct-non-list-initializes the contained value of rhs with std​::​move(*(*this)), followed by val->T​::​~T(); postcondition is that *this does not contain a value and rhs contains a value
no effect