39       return LHS.first < RHS;  in operator()
42       return LHS < RHS.first;  in operator()
65     if (empty() || K < begin()->first.first ||  in find()
66         K >= std::prev(end())->first.second)  in find()
72     if (K < I->first.second)  in find()
99     if (KS >= I->first.second)  in erase()
103     assert(KE <= I->first.second);  in erase()
109     if (KE < Tmp.first.second) {  in erase()
111           J, std::make_pair(std::make_pair(KE, Tmp.first.second), Tmp.second));  in erase()
116     if (KS > Tmp.first.first)  in erase()
118           J, std::make_pair(std::make_pair(Tmp.first.first, KS), Tmp.second));  in erase()
138     if (J != this->end() && KE == J->first.first && J->second == V) {  in insert()
139       KE = J->first.second;  in insert()
147       if (I->first.second == KS && I->second == V) {  in insert()
148         KS = I->first.first;  in insert()