9 Iterators library [iterators]

9.7 Iterator adaptors [iterators.predef]

9.7.4 Common iterators [iterators.common]

9.7.4.2 common_iterator operations [common.iter.ops]

9.7.4.2.6 common_iterator comparisons [common.iter.op.comp]

template <class I1, class I2, Sentinel<I2> S1, Sentinel<I1> S2> bool operator==( const common_iterator<I1, S1>& x, const common_iterator<I2, S2>& y);

1

Effects: Equivalent to: 

  return x.is_sentinel ?
    (y.is_sentinel || y.iter == x.sentinel) :
    (!y.is_sentinel || x.iter == y.sentinel);

template <class I1, class I2, Sentinel<I2> S1, Sentinel<I1> S2> requires EqualityComparableWith<I1, I2> bool operator==( const common_iterator<I1, S1>& x, const common_iterator<I2, S2>& y);

2

Effects: Equivalent to: 

  return x.is_sentinel ?
    (y.is_sentinel || y.iter == x.sentinel) :
    (y.is_sentinel ?
        x.iter == y.sentinel :
        x.iter == y.iter);

template <class I1, class I2, Sentinel<I2> S1, Sentinel<I1> S2> bool operator!=( const common_iterator<I1, S1>& x, const common_iterator<I2, S2>& y);

3

Effects: Equivalent to: return !(x == y);

template <class I2, SizedSentinel<I2> I1, SizedSentinel<I2> S1, SizedSentinel<I1> S2> difference_type_t<I2> operator-( const common_iterator<I1, S1>& x, const common_iterator<I2, S2>& y);

4

Effects: Equivalent to: 

  return x.is_sentinel ?
    (y.is_sentinel ? 0 : x.sentinel - y.iter) :
    (y.is_sentinel ?
         x.iter - y.sentinel :
         x.iter - y.iter);