Eroare de compilare: main.cpp: In function 'int main()': main.cpp:21:12: error: no match for 'operator==' (operand types are 'std::ifstream' {aka 'std::basic_ifstream<char>'} and 'std::nullptr_t') 21 | if (in == nullptr || out == nullptr) | ~~~^~~~~~~~~~ In file included from /usr/include/c++/12.2.1/string:41, from /usr/include/c++/12.2.1/bits/locale_classes.h:40, from /usr/include/c++/12.2.1/bits/ios_base.h:41, from /usr/include/c++/12.2.1/ios:42, from /usr/include/c++/12.2.1/ostream:38, from /usr/include/c++/12.2.1/iostream:39, from main.cpp:8: /usr/include/c++/12.2.1/bits/allocator.h:219:5: note: candidate: 'template<class _T1, class _T2> constexpr bool std::operator==(const allocator<_CharT>&, const allocator<_T2>&)' (reversed) 219 | operator==(const allocator<_T1>&, const allocator<_T2>&) | ^~~~~~~~ /usr/include/c++/12.2.1/bits/allocator.h:219:5: note: template argument deduction/substitution failed: main.cpp:21:15: note: mismatched types 'const std::allocator<_CharT>' and 'std::nullptr_t' 21 | if (in == nullptr || out == nullptr) | ^~~~~~~ In file included from /usr/include/c++/12.2.1/string:47: /usr/include/c++/12.2.1/bits/stl_iterator.h:530:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator==(const reverse_iterator<_IteratorL>&, const reverse_iterator<_IteratorR>&) requires requires{{std::operator==::__x->base() == std::operator==::__y->base()} -> decltype(auto) [requires std::convertible_to<<placeholder>, bool>];}' (reversed) 530 | operator==(const reverse_iterator<_IteratorL>& __x, | ^~~~~~~~ /usr/include/c++/12.2.1/bits/stl_iterator.h:530:5: note: template argument deduction/substitution failed: main.cpp:21:15: note: mismatched types 'const std::reverse_iterator<_IteratorL>' and 'std::nullptr_t' 21 | if (in == nullptr || out == nullptr) | ^~~~~~~ /usr/include/c++/12.2.1/bits/stl_iterator.h:1656:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator==(const move_iterator<_IteratorL>&, const move_iterator<_IteratorR>&) requires requires{{std::operator==::__x->base() == std::operator==::__y->base()} -> decltype(auto) [requires std::convertible_to<<placeholder>, bool>];}' (reversed) 1656 | operator==(const move_iterator<_IteratorL>& __x, | ^~~~~~~~ /usr/include/c++/12.2.1/bits/stl_iterator.h:1656:5: note: template argument deduction/substitution failed: main.cpp:21:15: note: mismatched types 'const std::move_iterator<_IteratorL>' and 'std::nullptr_t' 21 | if (in == nullptr || out == nullptr) | ^~~~~~~ In file included from /usr/include/c++/12.2.1/bits/basic_string.h:47, from /usr/include/c++/12.2.1/string:53: /usr/include/c++/12.2.1/string_view:546:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator==(basic_string_view<_CharT, _Traits>, __type_identity_t<basic_string_view<_CharT, _Traits> >)' (reversed) 546 | operator==(basic_string_view<_CharT, _Traits> __x, | ^~~~~~~~ /usr/include/c++/12.2.1/string_view:546:5: note: template argument deduction/substitution failed: main.cpp:21:15: note: mismatched types 'std::basic_string_view<_CharT, _Traits>' and 'std::nullptr_t' 21 | if (in == nullptr || out == nullptr) | ^~~~~~~ /usr/include/c++/12.2.1/bits/basic_string.h:3599:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> constexpr bool std::operator==(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const _CharT*)' (reversed) 3599 | operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs, | ^~~~~~~~ /usr/include/c++/12.2.1/bits/basic_string.h:3599:5: note: template argument deduction/substitution failed: main.cpp:21:15: note: mismatched types 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>' and 'std::nullptr_t' 21 | if (in == nullptr || out == nullptr) | ^~~~~~~ In file included from /usr/include/c++/12.2.1/bits/ios_base.h:46: Non zero exit status: 1