/in/foo.cc:1:1: error: 'include' does not name a type
    1 | include <iostream>
      | ^~~~~~~
In file included from /usr/include/c++/9/bits/stl_iterator_base_types.h:67,
                 from /usr/include/c++/9/numeric:61,
                 from /in/foo.cc:2:
/usr/include/c++/9/type_traits:361:31: error: 'std::size_t' has not been declared
  361 |   template<typename _Tp, std::size_t _Size>
      |                               ^~~~~~
/usr/include/c++/9/type_traits:362:25: error: '_Size' was not declared in this scope
  362 |     struct is_array<_Tp[_Size]>
      |                         ^~~~~
/usr/include/c++/9/type_traits:362:31: error: template argument 1 is invalid
  362 |     struct is_array<_Tp[_Size]>
      |                               ^
/usr/include/c++/9/type_traits:560:42: error: 'nullptr_t' is not a member of 'std'
  560 |     struct __is_null_pointer_helper<std::nullptr_t>
      |                                          ^~~~~~~~~
/usr/include/c++/9/type_traits:560:42: error: 'nullptr_t' is not a member of 'std'
/usr/include/c++/9/type_traits:560:51: error: template argument 1 is invalid
  560 |     struct __is_null_pointer_helper<std::nullptr_t>
      |                                                   ^
/usr/include/c++/9/type_traits:949:26: error: 'size_t' has not been declared
  949 |   template<typename _Tp, size_t _Num>
      |                          ^~~~~~
/usr/include/c++/9/type_traits:950:49: error: '_Num' was not declared in this scope
  950 |     struct __is_nt_constructible_impl<true, _Tp[_Num]>
      |                                                 ^~~~
/usr/include/c++/9/type_traits:950:54: error: template argument 2 is invalid
  950 |     struct __is_nt_constructible_impl<true, _Tp[_Num]>
      |                                                      ^
/usr/include/c++/9/type_traits:1246:37: error: 'size_t' is not a member of 'std'
 1246 |     : public integral_constant<std::size_t, alignof(_Tp)> { };
      |                                     ^~~~~~
/usr/include/c++/9/type_traits:1246:37: error: 'size_t' is not a member of 'std'
/usr/include/c++/9/type_traits:1246:57: error: template argument 1 is invalid
 1246 |     : public integral_constant<std::size_t, alignof(_Tp)> { };
      |                                                         ^
/usr/include/c++/9/type_traits:1246:57: note: invalid template non-type parameter
/usr/include/c++/9/type_traits:1251:37: error: 'size_t' is not a member of 'std'
 1251 |     : public integral_constant<std::size_t, 0> { };
      |                                     ^~~~~~
/usr/include/c++/9/type_traits:1251:37: error: 'size_t' is not a member of 'std'
/usr/include/c++/9/type_traits:1251:46: error: template argument 1 is invalid
 1251 |     : public integral_constant<std::size_t, 0> { };
      |                                              ^
/usr/include/c++/9/type_traits:1251:46: note: invalid template non-type parameter
/usr/include/c++/9/type_traits:1253:31: error: 'std::size_t' has not been declared
 1253 |   template<typename _Tp, std::size_t _Size>
      |                               ^~~~~~
/usr/include/c++/9/type_traits:1254:21: error: '_Size' was not declared in this scope
 1254 |     struct rank<_Tp[_Size]>
      |                     ^~~~~
/usr/include/c++/9/type_traits:1254:27: error: template argument 1 is invalid
 1254 |     struct rank<_Tp[_Size]>
      |                           ^
/usr/include/c++/9/type_traits:1255:37: error: 'size_t' is not a member of 'std'
 1255 |     : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
      |                                     ^~~~~~
/usr/include/c++/9/type_traits:1255:37: error: 'size_t' is not a member of 'std'
/usr/include/c++/9/type_traits:1255:65: error: template argument 1 is invalid
 1255 |     : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
      |                                                                 ^
/usr/include/c++/9/type_traits:1255:65: note: invalid template non-type parameter
/usr/include/c++/9/type_traits:1259:37: error: 'size_t' is not a member of 'std'
 1259 |     : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
      |                                     ^~~~~~
/usr/include/c++/9/type_traits:1259:37: error: 'size_t' is not a member of 'std'
/usr/include/c++/9/type_traits:1259:65: error: template argument 1 is invalid
 1259 |     : public integral_constant<std::size_t, 1 + rank<_Tp>::value> { };
      |                                                                 ^
/usr/include/c++/9/type_traits:1259:65: note: invalid template non-type parameter
/usr/include/c++/9/type_traits:1264:37: error: 'size_t' is not a member of 'std'
 1264 |     : public integral_constant<std::size_t, 0> { };
      |                                     ^~~~~~
/usr/include/c++/9/type_traits:1264:37: error: 'size_t' is not a member of 'std'
/usr/include/c++/9/type_traits:1264:46: error: template argument 1 is invalid
 1264 |     : public integral_constant<std::size_t, 0> { };
      |                                              ^
/usr/include/c++/9/type_traits:1264:46: note: invalid template non-type parameter
/usr/include/c++/9/type_traits:1266:47: error: 'std::size_t' has not been declared
 1266 |   template<typename _Tp, unsigned _Uint, std::size_t _Size>
      |                                               ^~~~~~
/usr/include/c++/9/type_traits:1267:23: error: '_Size' was not declared in this scope
 1267 |     struct extent<_Tp[_Size], _Uint>
      |                       ^~~~~
/usr/include/c++/9/type_traits:1267:36: error: template argument 1 is invalid
 1267 |     struct extent<_Tp[_Size], _Uint>
      |                                    ^
/usr/include/c++/9/type_traits:1268:37: error: 'size_t' is not a member of 'std'
 1268 |     : public integral_constant<std::size_t,
      |                                     ^~~~~~
/usr/include/c++/9/type_traits:1268:37: error: 'size_t' is not a member of 'std'
/usr/include/c++/9/type_traits:1269:24: error: '_Size' was not declared in this scope
 1269 |           _Uint == 0 ? _Size : extent<_Tp,
      |                        ^~~~~
/usr/include/c++/9/type_traits:1270:28: error: template argument 1 is invalid
 1270 |           _Uint - 1>::value>
      |                            ^
/usr/include/c++/9/type_traits:1270:28: note: invalid template non-type parameter
/usr/include/c++/9/type_traits:1275:37: error: 'size_t' is not a member of 'std'
 1275 |     : public integral_constant<std::size_t,
      |                                     ^~~~~~
/usr/include/c++/9/type_traits:1275:37: error: 'size_t' is not a member of 'std'
/usr/include/c++/9/type_traits:1277:31: error: template argument 1 is invalid
 1277 |              _Uint - 1>::value>
      |                               ^
/usr/include/c++/9/type_traits:1277:31: note: invalid template non-type parameter
/usr/include/c++/9/type_traits:1610:26: error: 'size_t' does not name a type
 1610 |       { static constexpr size_t __size = sizeof(_Tp); };
      |                          ^~~~~~
In file included from /usr/include/c++/9/bits/stl_iterator_base_types.h:67,
                 from /usr/include/c++/9/numeric:61,
                 from /in/foo.cc:2:
/usr/include/c++/9/type_traits:1:1: note: 'size_t' is defined in header '<cstddef>'; did you forget to '#include <cstddef>'?
  +++ |+#include <cstddef>
    1 | // C++11 <type_traits> -*- C++ -*-
In file included from /usr/include/c++/9/bits/stl_iterator_base_types.h:67,
                 from /usr/include/c++/9/numeric:61,
                 from /in/foo.cc:2:
/usr/include/c++/9/type_traits:1612:14: error: 'size_t' has not been declared
 1612 |     template<size_t _Sz, typename _Tp, bool = (_Sz <= _Tp::__size)>
      |              ^~~~~~
/usr/include/c++/9/type_traits:1612:48: error: '_Sz' was not declared in this scope
 1612 |     template<size_t _Sz, typename _Tp, bool = (_Sz <= _Tp::__size)>
      |                                                ^~~
/usr/include/c++/9/type_traits:1613:14: error: no default argument for '_Tp'
 1613 |       struct __select;
      |              ^~~~~~~~
/usr/include/c++/9/type_traits: