any& operator=( const any& rhs );

any& operator=( any&& rhs );

template<typename ValueType>
    any& operator=( ValueType&& rhs );

1) Assigns by copying the state of rhs, as if by any(rhs).swap(*this).

2) Assigns by moving the state of rhs, as if by any(std::move(rhs)).swap(*this). rhs is left in a valid but unspecified state after the assignment.

3) Assigns the type and value of rhs, as if by any(std::forward<ValueType>(rhs)).swap(*this). If std::is_copy_constructible<std::decay_t<ValueType>>::value is false, the program is ill-formed. This overload only participates in overload resolution if std::decay_t<ValueType> is not the same type as any.

2)

1,3) Throws bad_alloc or any exception thrown by the constructor of the contained type. If an exception is thrown, there are no effects (strong exception guarantee).