void setnext(size_t n){
size_t nelem = v.size();
if( n != nelem ){
v = b(c);
}
next = v.begin() + n;
}
const_iterator_pair merge_range(const range_type& key) const
{
const_iterator_pair sequence( equal_range( key ) );
if ( sequence.first != m_set.begin() && ( --sequence.first )->end() < key.begin() )
++sequence.first;
if ( sequence.second != m_set.end() && sequence.second->begin() == key.end() )
++sequence.second;
return sequence;
}
range_size_type merge_and_replace(container_type& set,
iterator_pair sequence, const range_type& new_range)
{
ASSERT( sequence.first != sequence.second );
if ( sequence.first->begin() <= new_range.begin()
&& sequence.first->end() >= new_range.end() ) return 0;
range_size_type old_sum = m_length_sum;
range_size_type low = min( sequence.first->begin(), new_range.begin() );
range_size_type high = max( ( --sequence.second )->end(), new_range.end() );
for ( ++sequence.second; sequence.first != sequence.second; )
{
range_size_type length = sequence.first->size();
set.erase( sequence.first++ );
m_length_sum -= length;
}
set.insert( sequence.second, range_type( low, high ) );
m_length_sum += high - low;
return m_length_sum - old_sum;
}
range_size_type overlapping_sum(const range_type& key) const
{
const_iterator_pair sequence( equal_range( key ) );
range_size_type sum = 0;
for ( ; sequence.first != sequence.second; ++sequence.first )
{
sum += min( sequence.first->end(), key.end() )
- max( sequence.first->begin(), key.begin() );
}
return sum;
}
size_t nth() const { return next - v.begin(); }