/in/foo.cc: In function 'std::istream& operator>>(std::istream&, const Complex&)':
/in/foo.cc:24:12: error: no match for 'operator>>' (operand types are 'std::istream' {aka 'std::basic_istream<char>'} and 'const double')
   24 |         is >> c.real >> " " >> c.imag;
      |         ~~ ^~ ~~~~~~
      |         |       |
      |         |       const double
      |         std::istream {aka std::basic_istream<char>}
In file included from /usr/include/c++/12/iostream:40,
                 from /in/foo.cc:1:
/usr/include/c++/12/istream:168:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(bool&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  168 |       operator>>(bool& __n)
      |       ^~~~~~~~
/usr/include/c++/12/istream:168:7: note:   conversion of argument 1 would be ill-formed:
/in/foo.cc:24:17: error: cannot bind non-const lvalue reference of type 'bool&' to a value of type 'double'
   24 |         is >> c.real >> " " >> c.imag;
      |               ~~^~~~
/usr/include/c++/12/istream:172:7: note: candidate: 'std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(short int&) [with _CharT = char; _Traits = std::char_traits<char>]' (near match)
  172 |       operator>>(short& __n);
      |       ^~~~~~~~
/usr/include/c++/12/istream:172:7: note:   conversion of argument 1 would be ill-formed:
/in/foo.cc:24:17: error: cannot bind non-const lvalue reference of type 'short int&' to a value of type 'double'
   24 |         is >> c.real >> " " >> c.imag;
      |               ~~^~~~
/usr/include/c++/12/istream:175:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(short unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  175 |       operator>>(unsigned short& __n)
      |       ^~~~~~~~
/usr/include/c++/12/istream:175:7: note:   conversion of argument 1 would be ill-formed:
/in/foo.cc:24:17: error: cannot bind non-const lvalue reference of type 'short unsigned int&' to a value of type 'double'
   24 |         is >> c.real >> " " >> c.imag;
      |               ~~^~~~
/usr/include/c++/12/istream:179:7: note: candidate: 'std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::operator>>(int&) [with _CharT = char; _Traits = std::char_traits<char>]' (near match)
  179 |       operator>>(int& __n);
      |       ^~~~~~~~
/usr/include/c++/12/istream:179:7: note:   conversion of argument 1 would be ill-formed:
/in/foo.cc:24:17: error: cannot bind non-const lvalue reference of type 'int&' to a value of type 'double'
   24 |         is >> c.real >> " " >> c.imag;
      |               ~~^~~~
/usr/include/c++/12/istream:182:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  182 |       operator>>(unsigned int& __n)
      |       ^~~~~~~~
/usr/include/c++/12/istream:182:7: note:   conversion of argument 1 would be ill-formed:
/in/foo.cc:24:17: error: cannot bind non-const lvalue reference of type 'unsigned int&' to a value of type 'double'
   24 |         is >> c.real >> " " >> c.imag;
      |               ~~^~~~
/usr/include/c++/12/istream:186:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  186 |       operator>>(long& __n)
      |       ^~~~~~~~
/usr/include/c++/12/istream:186:7: note:   conversion of argument 1 would be ill-formed:
/in/foo.cc:24:17: error: cannot bind non-const lvalue reference of type 'long int&' to a value of type 'double'
   24 |         is >> c.real >> " " >> c.imag;
      |               ~~^~~~
/usr/include/c++/12/istream:190:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  190 |       operator>>(unsigned long& __n)
      |       ^~~~~~~~
/usr/include/c++/12/istream:190:7: note:   conversion of argument 1 would be ill-formed:
/in/foo.cc:24:17: error: cannot bind non-const lvalue reference of type 'long unsigned int&' to a value of type 'double'
   24 |         is >> c.real >> " " >> c.imag;
      |               ~~^~~~
/usr/include/c++/12/istream:195:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  195 |       operator>>(long long& __n)
      |       ^~~~~~~~
/usr/include/c++/12/istream:195:7: note:   conversion of argument 1 would be ill-formed:
/in/foo.cc:24:17: error: cannot bind non-const lvalue reference of type 'long long int&' to a value of type 'double'
   24 |         is >> c.real >> " " >> c.imag;
      |               ~~^~~~
/usr/include/c++/12/istream:199:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long long unsigned int&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  199 |       operator>>(unsigned long long& __n)
      |       ^~~~~~~~
/usr/include/c++/12/istream:199:7: note:   conversion of argument 1 would be ill-formed:
/in/foo.cc:24:17: error: cannot bind non-const lvalue reference of type 'long long unsigned int&' to a value of type 'double'
   24 |         is >> c.real >> " " >> c.imag;
      |               ~~^~~~
/usr/include/c++/12/istream:214:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(float&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  214 |       operator>>(float& __f)
      |       ^~~~~~~~
/usr/include/c++/12/istream:214:7: note:   conversion of argument 1 would be ill-formed:
/in/foo.cc:24:17: error: cannot bind non-const lvalue reference of type 'float&' to a value of type 'double'
   24 |         is >> c.real >> " " >> c.imag;
      |               ~~^~~~
/usr/include/c++/12/istream:218:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(double&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  218 |       operator>>(double& __f)
      |       ^~~~~~~~
/usr/include/c++/12/istream:218:7: note:   conversion of argument 1 would be ill-formed:
/in/foo.cc:24:17: error: binding reference of type 'double&' to 'const double' discards qualifiers
   24 |         is >> c.real >> " " >> c.imag;
      |               ~~^~~~
/usr/include/c++/12/istream:222:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(long double&) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]' (near match)
  222 |       operator>>(long double& __f)
      |       ^~~~~~~~
/usr/include/c++/12/istream:222:7: note:   conversion of argument 1 would be ill-formed:
/in/foo.cc:24:17: error: cannot bind non-const lvalue reference of type 'long double&' to a value of type 'double'
   24 |         is >> c.real >> " " >> c.imag;
      |               ~~^~~~
/usr/include/c++/12/istream:120:7: note: candidate: 'std::basic_istream<_CharT, _Traits>::__istream_type& std::basic_istream<_CharT, _Traits>::operator>>(__istream_type& (*)(__istream_type&)) [with _CharT = char; _Traits = std::char_traits<char>; __istream_type = std::basic_istream<char>]'
  120 |       operator>>(__istream_type&