STObject::OptionalProxy::operator==

friend bool
operator==(
    OptionalProxy const& lhs,
    boost::none_t);

friend bool
operator==(
    boost::none_t,
    OptionalProxy const& rhs);

friend bool
operator==(
    OptionalProxy const& lhs,
    optional_type const& rhs);

friend bool
operator==(
    optional_type const& lhs,
    OptionalProxy const& rhs);

friend bool
operator==(
    OptionalProxy const& lhs,
    OptionalProxy const& rhs);