snake_escaping.cpp: In lambda function:
snake_escaping.cpp:27:17: error: no match for 'operator=' (operand types are 'std::tuple<int&, int&>' and '__gnu_cxx::__alloc_traits<std::allocator<std::array<int, 2> >, std::array<int, 2> >::value_type' {aka 'std::array<int, 2>'})
27 | #define bk back()
| ^
snake_escaping.cpp:104:29: note: in expansion of macro 'bk'
104 | tie(l, r) = lrs.bk;
| ^~
In file included from /usr/include/c++/11/functional:54,
from /usr/include/c++/11/pstl/glue_algorithm_defs.h:13,
from /usr/include/c++/11/algorithm:74,
from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:65,
from snake_escaping.cpp:1:
/usr/include/c++/11/tuple:1290:9: note: candidate: 'template<class _U1, class _U2> std::__enable_if_t<__assignable<const _U1&, const _U2&>(), std::tuple<_T1, _T2>&> std::tuple<_T1, _T2>::operator=(const std::tuple<_U1, _U2>&) [with _U1 = _U1; _U2 = _U2; _T1 = int&; _T2 = int&]'
1290 | operator=(const tuple<_U1, _U2>& __in)
| ^~~~~~~~
/usr/include/c++/11/tuple:1290:9: note: template argument deduction/substitution failed:
snake_escaping.cpp:27:17: note: '__gnu_cxx::__alloc_traits<std::allocator<std::array<int, 2> >, std::array<int, 2> >::value_type' {aka 'std::array<int, 2>'} is not derived from 'const std::tuple<_T1, _T2>'
27 | #define bk back()
| ^
snake_escaping.cpp:104:29: note: in expansion of macro 'bk'
104 | tie(l, r) = lrs.bk;
| ^~
In file included from /usr/include/c++/11/functional:54,
from /usr/include/c++/11/pstl/glue_algorithm_defs.h:13,
from /usr/include/c++/11/algorithm:74,
from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:65,
from snake_escaping.cpp:1:
/usr/include/c++/11/tuple:1300:9: note: candidate: 'template<class _U1, class _U2> std::__enable_if_t<__assignable<_U1, _U2>(), std::tuple<_T1, _T2>&> std::tuple<_T1, _T2>::operator=(std::tuple<_U1, _U2>&&) [with _U1 = _U1; _U2 = _U2; _T1 = int&; _T2 = int&]'
1300 | operator=(tuple<_U1, _U2>&& __in)
| ^~~~~~~~
/usr/include/c++/11/tuple:1300:9: note: template argument deduction/substitution failed:
snake_escaping.cpp:27:17: note: '__gnu_cxx::__alloc_traits<std::allocator<std::array<int, 2> >, std::array<int, 2> >::value_type' {aka 'std::array<int, 2>'} is not derived from 'std::tuple<_T1, _T2>'
27 | #define bk back()
| ^
snake_escaping.cpp:104:29: note: in expansion of macro 'bk'
104 | tie(l, r) = lrs.bk;
| ^~
In file included from /usr/include/c++/11/functional:54,
from /usr/include/c++/11/pstl/glue_algorithm_defs.h:13,
from /usr/include/c++/11/algorithm:74,
from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:65,
from snake_escaping.cpp:1:
/usr/include/c++/11/tuple:1310:9: note: candidate: 'template<class _U1, class _U2> std::__enable_if_t<__assignable<const _U1&, const _U2&>(), std::tuple<_T1, _T2>&> std::tuple<_T1, _T2>::operator=(const std::pair<_U1, _U2>&) [with _U1 = _U1; _U2 = _U2; _T1 = int&; _T2 = int&]'
1310 | operator=(const pair<_U1, _U2>& __in)
| ^~~~~~~~
/usr/include/c++/11/tuple:1310:9: note: template argument deduction/substitution failed:
snake_escaping.cpp:27:17: note: '__gnu_cxx::__alloc_traits<std::allocator<std::array<int, 2> >, std::array<int, 2> >::value_type' {aka 'std::array<int, 2>'} is not derived from 'const std::pair<_T1, _T2>'
27 | #define bk back()
| ^
snake_escaping.cpp:104:29: note: in expansion of macro 'bk'
104 | tie(l, r) = lrs.bk;
| ^~
In file included from /usr/include/c++/11/functional:54,
from /usr/include/c++/11/pstl/glue_algorithm_defs.h:13,
from /usr/include/c++/11/algorithm:74,
from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:65,
from snake_escaping.cpp:1:
/usr/include/c++/11/tuple:1321:9: note: candidate: 'template<class _U1, class _U2> std::__enable_if_t<__assignable<_U1, _U2>(), std::tuple<_T1, _T2>&> std::tuple<_T1, _T2>::operator=(std::pair<_U1, _U2>&&) [with _U1 = _U1; _U2 = _U2; _T1 = int&; _T2 = int&]'
1321 | operator=(pair<_U1, _U2>&& __in)
| ^~~~~~~~
/usr/include/c++/11/tuple:1321:9: note: template argument deduction/substitution failed:
snake_escaping.cpp:27:17: note: '__gnu_cxx::__alloc_traits<std::allocator<std::array<int, 2> >, std::array<int, 2> >::value_type' {aka 'std::array<int, 2>'} is not derived from 'std::pair<_T1, _T2>'
27 | #define bk back()
| ^
snake_escaping.cpp:104:29: note: in expansion of macro 'bk'
104 | tie(l, r) = lrs.bk;
| ^~
In file included from /usr/include/c++/11/functional:54,
from /usr/include/c++/11/pstl/glue_algorithm_defs.h:13,
from /usr/include/c++/11/algorithm:74,
from /usr/include/x86_64-linux-gnu/c++/11/bits/stdc++.h:65,
from snake_escaping.cpp:1:
/usr/include/c++/11/tuple:1267:7: note: candidate: 'std::tuple<_T1, _T2>& std::tuple<_T1, _T2>::operator=(typename std::conditional<__assignable<const _T1&, const _T2&>(), const std::tuple<_T1, _T2>&, const std::__nonesuch&>::type) [with _T1 = int&; _T2 = int&; typename std::conditional<__assignable<const _T1&, const _T2&>(), const std::tuple<_T1, _T2>&, const std::__nonesuch&>::type = const std::tuple<int&, int&>&]'
1267 | operator=(typename conditional<__assignable<const _T1&, const _T2&>(),
| ^~~~~~~~
/usr/include/c++/11/tuple:1269:63: note: no known conversion for argument 1 from '__gnu_cxx::__alloc_traits<std::allocator<std::array<int, 2> >, std::array<int, 2> >::value_type' {aka 'std::array<int, 2>'} to 'std::conditional<true, const std::tuple<int&, int&>&, const std::__nonesuch&>::type' {aka 'const std::tuple<int&, int&>&'}
1267 | operator=(typename conditional<__assignable<const _T1&, const _T2&>(),
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1268 | const tuple&,
| ~~~~~~~~~~~~~
1269 | const __nonesuch&>::type __in)
| ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
/usr/include/c++/11/tuple:1278:7: note: candidate: 'std::tuple<_T1, _T2>& std::tuple<_T1, _T2>::operator=(typename std::conditional<__assignable<_T1, _T2>(), std::tuple<_T1, _T2>&&, std::__nonesuch&&>::type) [with _T1 = int&; _T2 = int&; typename std::conditional<__assignable<_T1, _T2>(), std::tuple<_T1, _T2>&&, std::__nonesuch&&>::type = std::tuple<int&, int&>&&]'
1278 | operator=(typename conditional<__assignable<_T1, _T2>(),
| ^~~~~~~~
/usr/include/c++/11/tuple:1280:58: note: no known conversion for argument 1 from '__gnu_cxx::__alloc_traits<std::allocator<std::array<int, 2> >, std::array<int, 2> >::value_type' {aka 'std::array<int, 2>'} to 'std::conditional<true, std::tuple<int&, int&>&&, std::__nonesuch&&>::type' {aka 'std::tuple<int&, int&>&&'}
1278 | operator=(typename conditional<__assignable<_T1, _T2>(),
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1279 | tuple&&,
| ~~~~~~~~
1280 | __nonesuch&&>::type __in)
| ~~~~~~~~~~~~~~~~~~~~^~~~