std::experimental::ranges::tagged<Base,Tags...>:: operator=

From cppreference.com
tagged & operator = ( tagged && that ) = default ;
(1)
tagged & operator = ( const tagged & that ) = default ;
(2)
template < class Other >

requires Assignable < Base & , Other >
constexpr tagged & operator = ( ranges:: tagged < Other, Tags... > && that )

noexcept ( std:: is_nothrow_assignable < Base & , Other > :: value ) ;
(3)
template < class Other >

requires Assignable < Base & , const Other & >

constexpr tagged & operator = ( const ranges:: tagged < Other, Tags... > & that ) ;
(4)
template < class U >

requires Assignable < Base & , U > && ! Same < std:: decay_t < U > , tagged >

constexpr tagged & operator = ( U && that ) noexcept ( std:: is_nothrow_assignable < Base & , U > :: value ) ;
(5)

Assigns the contents of that to * this .

1,2) tagged has defaulted copy and move assignment operators that invoke the corresponding assignment operator of Base .
3) Converting move assignment from a different tagged specialization with matching tags. Equivalent to static_cast < Base & > ( * this ) = static_cast < Other && > ( that ) ; .
4) Converting copy assignment from a different tagged specialization with matching tags. Equivalent to static_cast < Base & > ( * this ) = static_cast < const Other & > ( that ) ; .
5) Assigns that to the Base subobject. Equivalent to static_cast < Base & > ( * this ) = std:: forward < U > ( that ) ; .

Return value

* this .