tri.cpp: In function 'int main()':
tri.cpp:70:48: warning: right operand of comma operator has no effect [-Wunused-value]
   70 |       while (SZ(hull)>=2 && (hull[SZ(hull)-2], p, hull[SZ(hull)-1]) <= 0) {
      |                                                ^
tri.cpp:70:69: error: no match for 'operator<=' (operand types are '__gnu_cxx::__alloc_traits<std::allocator<pt>, pt>::value_type' {aka 'pt'} and 'int')
   70 |       while (SZ(hull)>=2 && (hull[SZ(hull)-2], p, hull[SZ(hull)-1]) <= 0) {
      |                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^~ ~
      |                                                 |                      |
      |                                                 |                      int
      |                                                 __gnu_cxx::__alloc_traits<std::allocator<pt>, pt>::value_type {aka pt}
In file included from /usr/include/c++/10/regex:62,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:110,
                 from tri.cpp:1:
/usr/include/c++/10/bits/regex.h:1086:5: note: candidate: 'template<class _BiIter> bool std::__cxx11::operator<=(const std::__cxx11::sub_match<_BiIter>&, const std::__cxx11::sub_match<_BiIter>&)'
 1086 |     operator<=(const sub_match<_BiIter>& __lhs, const sub_match<_BiIter>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/10/bits/regex.h:1086:5: note:   template argument deduction/substitution failed:
tri.cpp:70:72: note:   '__gnu_cxx::__alloc_traits<std::allocator<pt>, pt>::value_type' {aka 'pt'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   70 |       while (SZ(hull)>=2 && (hull[SZ(hull)-2], p, hull[SZ(hull)-1]) <= 0) {
      |                                                                        ^
In file included from /usr/include/c++/10/regex:62,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:110,
                 from tri.cpp:1:
/usr/include/c++/10/bits/regex.h:1192:5: note: candidate: 'template<class _Bi_iter, class _Ch_traits, class _Ch_alloc> bool std::__cxx11::operator<=(std::__cxx11::__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>&, const std::__cxx11::sub_match<_BiIter>&)'
 1192 |     operator<=(const __sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/10/bits/regex.h:1192:5: note:   template argument deduction/substitution failed:
tri.cpp:70:72: note:   '__gnu_cxx::__alloc_traits<std::allocator<pt>, pt>::value_type' {aka 'pt'} is not derived from 'std::__cxx11::__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>'
   70 |       while (SZ(hull)>=2 && (hull[SZ(hull)-2], p, hull[SZ(hull)-1]) <= 0) {
      |                                                                        ^
In file included from /usr/include/c++/10/regex:62,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:110,
                 from tri.cpp:1:
/usr/include/c++/10/bits/regex.h:1285:5: note: candidate: 'template<class _Bi_iter, class _Ch_traits, class _Ch_alloc> bool std::__cxx11::operator<=(const std::__cxx11::sub_match<_BiIter>&, std::__cxx11::__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>&)'
 1285 |     operator<=(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/10/bits/regex.h:1285:5: note:   template argument deduction/substitution failed:
tri.cpp:70:72: note:   '__gnu_cxx::__alloc_traits<std::allocator<pt>, pt>::value_type' {aka 'pt'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   70 |       while (SZ(hull)>=2 && (hull[SZ(hull)-2], p, hull[SZ(hull)-1]) <= 0) {
      |                                                                        ^
In file included from /usr/include/c++/10/regex:62,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:110,
                 from tri.cpp:1:
/usr/include/c++/10/bits/regex.h:1359:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<=(const typename std::iterator_traits<_Iter>::value_type*, const std::__cxx11::sub_match<_BiIter>&)'
 1359 |     operator<=(typename iterator_traits<_Bi_iter>::value_type const* __lhs,
      |     ^~~~~~~~
/usr/include/c++/10/bits/regex.h:1359:5: note:   template argument deduction/substitution failed:
tri.cpp:70:72: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'int'
   70 |       while (SZ(hull)>=2 && (hull[SZ(hull)-2], p, hull[SZ(hull)-1]) <= 0) {
      |                                                                        ^
In file included from /usr/include/c++/10/regex:62,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:110,
                 from tri.cpp:1:
/usr/include/c++/10/bits/regex.h:1453:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<=(const std::__cxx11::sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type*)'
 1453 |     operator<=(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/10/bits/regex.h:1453:5: note:   template argument deduction/substitution failed:
tri.cpp:70:72: note:   '__gnu_cxx::__alloc_traits<std::allocator<pt>, pt>::value_type' {aka 'pt'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   70 |       while (SZ(hull)>=2 && (hull[SZ(hull)-2], p, hull[SZ(hull)-1]) <= 0) {
      |                                                                        ^
In file included from /usr/include/c++/10/regex:62,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:110,
                 from tri.cpp:1:
/usr/include/c++/10/bits/regex.h:1531:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<=(const typename std::iterator_traits<_Iter>::value_type&, const std::__cxx11::sub_match<_BiIter>&)'
 1531 |     operator<=(typename iterator_traits<_Bi_iter>::value_type const& __lhs,
      |     ^~~~~~~~
/usr/include/c++/10/bits/regex.h:1531:5: note:   template argument deduction/substitution failed:
tri.cpp:70:72: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'int'
   70 |       while (SZ(hull)>=2 && (hull[SZ(hull)-2], p, hull[SZ(hull)-1]) <= 0) {
      |                                                                        ^
In file included from /usr/include/c++/10/regex:62,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:110,
                 from tri.cpp:1:
/usr/include/c++/10/bits/regex.h:1631:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<=(const std::__cxx11::sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type&)'
 1631 |     operator<=(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/10/bits/regex.h:1631:5: note:   template argument deduction/substitution failed:
tri.cpp:70:72: note:   '__gnu_cxx::__alloc_traits<std::allocator<pt>, pt>::value_type' {aka 'pt'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   70 |       while (SZ(hull)>=2 && (hull[SZ(hull)-2], p, hull[SZ(hull)-1]) <= 0) {
      |                                                                        ^
In file included from /usr/include/c++/10/bits/stl_algobase.h:64,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from tri.cpp:1:
/usr/include/c++/10/bits/stl_pair.h:508:5: note: candidate: 'template<class _T1, class _T2> constexpr bool std::operator<=(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&)'
  508 |     operator<=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
      |     ^~~~~~~~
/usr/include/c++/10/bits/stl_pair.h:508:5: note:   template argument deduction/substitution failed:
tri.cpp:70:72: note:   '__gnu_cxx::__alloc_traits<std::allocator<pt>, pt>::value_type' {aka 'pt'} is not derived from 'const std::pair<_T1, _T2>'
   70 |       while (SZ(hull)>=2 && (hull[SZ(hull)-2], p, hull[SZ(hull)-1]) <= 0) {
      |                                                                        ^
In file included from /usr/include/c++/10/bits/stl_algobase.h:67,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from tri.cpp:1:
/usr/include/c++/10/bits/stl_iterator.h:384:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator<=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&)'
  384 |     operator<=(const reverse_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/10/bits/stl_iterator.h:384:5: note:   template argument deduction/substitution failed:
tri.cpp:70:72: note:   '__gnu_cxx::__alloc_traits<std::allocator<pt>, pt>::value_type' {aka 'pt'} is not derived from 'const std::reverse_iterator<_Iterator>'
   70 |       while (SZ(hull)>=2 && (hull[SZ(hull)-2], p, hull[SZ(hull)-1]) <= 0) {
      |                                                                        ^
In file included from /usr/include/c++/10/bits/stl_algobase.h:67,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from tri.cpp:1:
/usr/include/c++/10/bits/stl_iterator.h:422:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator<=(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&)'
  422 |     operator<=(const reverse_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/10/bits/stl_iterator.h:422:5: note:   template argument deduction/substitution failed:
tri.cpp:70:72: note:   '__gnu_cxx::__alloc_traits<std::allocator<pt>, pt>::value_type' {aka 'pt'} is not derived from 'const std::reverse_iterator<_Iterator>'
   70 |       while (SZ(hull)>=2 && (hull[SZ(hull)-2], p, hull[SZ(hull)-1]) <= 0) {
      |                                                                        ^
In file included from /usr/include/c++/10/bits/stl_algobase.h:67,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from tri.cpp:1:
/usr/include/c++/10/bits/stl_iterator.h:1460:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator<=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorR>&)'
 1460 |     operator<=(const move_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/10/bits/stl_iterator.h:1460:5: note:   template argument deduction/substitution failed:
tri.cpp:70:72: note:   '__gnu_cxx::__alloc_traits<std::allocator<pt>, pt>::value_type' {aka 'pt'} is not derived from 'const std::move_iterator<_IteratorL>'
   70 |       while (SZ(hull)>=2 && (hull[SZ(hull)-2], p, hull[SZ(hull)-1]) <= 0) {
      |                                                                        ^
In file included from /usr/include/c++/10/bits/stl_algobase.h:67,
                 from /usr/include/c++/10/bits/specfun.h:45,
                 from /usr/include/c++/10/cmath:1927,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:41,
                 from tri.cpp:1:
/usr/include/c++/10/bits/stl_iterator.h:1513:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator<=(const std::move_iterator<_IteratorL>&, const std::move_iterator<_IteratorL>&)'
 1513 |     operator<=(const move_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/10/bits/stl_iterator.h:1513:5: note:   template argument deduction/substitution failed:
tri.cpp:70:72: note:   '__gnu_cxx::__alloc_traits<std::allocator<pt>, pt>::value_type' {aka 'pt'} is not derived from 'const std::move_iterator<_IteratorL>'
   70 |       while (SZ(hull)>=2 && (hull[SZ(hull)-2], p, hull[SZ(hull)-1]) <= 0) {
      |                                                                        ^
In file included from /usr/include/c++/10/bits/basic_string.h:48,
                 from /usr/include/c++/10/string:55,
                 from /usr/include/c++/10/bits/locale_classes.h:40,
                 from /usr/include/c++/10/bits/ios_base.h:41,
                 from /usr/include/c++/10/ios:42,
                 from /usr/include/c++/10/istream:38,
                 from /usr/include/c++/10/sstream:38,
                 from /usr/include/c++/10/complex:45,
                 from /usr/include/c++/10/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:54,
                 from tri.cpp:1:
/usr/include/c++/10/string_view:582:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator<=(std::basic_string_view<_CharT, _Traits>, std::basic_string_view<_CharT, _Traits>)'
  582 |     operator<=(basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/10/string_view:582:5: note:   template argument deduction/substitution failed:
tri.cpp:70:72: note:   'pt' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   70 |       while (SZ(hull)>=2 && (hull[SZ(hull)-2], p, hull[SZ(hull)-1]) <= 0) {
      |                                                                        ^
In file included from /usr/include/c++/10/bits/basic_string.h:48,
                 from /usr/include/c++/10/string:55,
                 from /usr/include/c++/10/bits/locale_classes.h:40,
                 from /usr/include/c++/10/bits/ios_base.h:41,
                 from /usr/include/c++/10/ios:42,
                 from /usr/include/c++/10/istream:38,
                 from /usr/include/c++/10/sstream:38,
                 from /usr/include/c++/10/complex:45,
                 from /usr/include/c++/10/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:54,
                 from tri.cpp:1:
/usr/include/c++/10/string_view:588:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator<=(std::basic_string_view<_CharT, _Traits>, std::__type_identity_t<std::basic_string_view<_CharT, _Traits> >)'
  588 |     operator<=(basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/10/string_view:588:5: note:   template argument deduction/substitution failed:
tri.cpp:70:72: note:   'pt' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   70 |       while (SZ(hull)>=2 && (hull[SZ(hull)-2], p, hull[SZ(hull)-1]) <= 0) {
      |                                                                        ^
In file included from /usr/include/c++/10/bits/basic_string.h:48,
                 from /usr/include/c++/10/string:55,
                 from /usr/include/c++/10/bits/locale_classes.h:40,
                 from /usr/include/c++/10/bits/ios_base.h:41,
                 from /usr/include/c++/10/ios:42,
                 from /usr/include/c++/10/istream:38,
                 from /usr/include/c++/10/sstream:38,
                 from /usr/include/c++/10/complex:45,
                 from /usr/include/c++/10/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:54,
                 from tri.cpp:1:
/usr/include/c++/10/string_view:595:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator<=(std::__type_identity_t<std::basic_string_view<_CharT, _Traits> >, std::basic_string_view<_CharT, _Traits>)'
  595 |     operator<=(__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
      |     ^~~~~~~~
/usr/include/c++/10/string_view:595:5: note:   template argument deduction/substitution failed:
tri.cpp:70:72: note:   mismatched types 'std::basic_string_view<_CharT, _Traits>' and 'int'
   70 |       while (SZ(hull)>=2 && (hull[SZ(hull)-2], p, hull[SZ(hull)-1]) <= 0) {
      |                                                                        ^
In file included from /usr/include/c++/10/string:55,
                 from /usr/include/c++/10/bits/locale_classes.h:40,
                 from /usr/include/c++/10/bits/ios_base.h:41,
                 from /usr/include/c++/10/ios:42,
                 from /usr/include/c++/10/istream:38,
                 from /usr/include/c++/10/sstream:38,
                 from /usr/include/c++/10/complex:45,
                 from /usr/include/c++/10/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:54,
                 from tri.cpp:1:
/usr/include/c++/10/bits/basic_string.h:6343:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator<=(const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&, const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 6343 |     operator<=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/10/bits/basic_string.h:6343:5: note:   template argument deduction/substitution failed:
tri.cpp:70:72: note:   '__gnu_cxx::__alloc_traits<std::allocator<pt>, pt>::value_type' {aka 'pt'} is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   70 |       while (SZ(hull)>=2 && (hull[SZ(hull)-2], p, hull[SZ(hull)-1]) <= 0) {
      |                                                                        ^
In file included from /usr/include/c++/10/string:55,
                 from /usr/include/c++/10/bits/locale_classes.h:40,
                 from /usr/include/c++/10/bits/ios_base.h:41,
                 from /usr/include/c++/10/ios:42,
                 from /usr/include/c++/10/istream:38,
                 from /usr/include/c++/10/sstream:38,
                 from /usr/include/c++/10/complex:45,
                 from /usr/include/c++/10/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:54,
                 from tri.cpp:1:
/usr/include/c++/10/bits/basic_string.h:6356:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator<=(const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>&, const _CharT*)'
 6356 |     operator<=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/10/bits/basic_string.h:6356:5: note:   template argument deduction/substitution failed:
tri.cpp:70:72: note:   '__gnu_cxx::__alloc_traits<std::allocator<pt>, pt>::value_type' {aka 'pt'} is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   70 |       while (SZ(hull)>=2 && (hull[SZ(hull)-2], p, hull[SZ(hull)-1]) <= 0) {
      |                                                                        ^
In file included from /usr/include/c++/10/string:55,
                 from /usr/include/c++/10/bits/local