foo.cc: In function 'int main()':
foo.cc:9:13: error: no match for 'operator=' (operand types are 'std::basic_ostream<char>' and 'int')
    9 | cout<<a=1+2+3;
      |             ^
In file included from iostream:39:
/nix/store/h5kvfrjmpw792v8jg7nrzfkffmn0iyy8-gcc-12.3.0/include/c++/12.3.0/ostream:402:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator=(std::basic_ostream<_CharT, _Traits>&&) [with _CharT = char; _Traits = std::char_traits<char>]'
  402 |       operator=(basic_ostream&& __rhs)
      |       ^~~~~~~~
/nix/store/h5kvfrjmpw792v8jg7nrzfkffmn0iyy8-gcc-12.3.0/include/c++/12.3.0/ostream:402:33: note:   no known conversion for argument 1 from 'int' to 'std::basic_ostream<char>&&'
  402 |       operator=(basic_ostream&& __rhs)
      |                 ~~~~~~~~~~~~~~~~^~~~~
foo.cc:12:13: error: no match for 'operator=' (operand types are 'std::basic_ostream<char>' and 'int')
   12 | cout<<b=2+6+9;
      |             ^
/nix/store/h5kvfrjmpw792v8jg7nrzfkffmn0iyy8-gcc-12.3.0/include/c++/12.3.0/ostream:402:7: note: candidate: 'std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::operator=(std::basic_ostream<_CharT, _Traits>&&) [with _CharT = char; _Traits = std::char_traits<char>]'
  402 |       operator=(basic_ostream&& __rhs)
      |       ^~~~~~~~
/nix/store/h5kvfrjmpw792v8jg7nrzfkffmn0iyy8-gcc-12.3.0/include/c++/12.3.0/ostream:402:33: note:   no known conversion for argument 1 from 'int' to 'std::basic_ostream<char>&&'
  402 |       operator=(basic_ostream&& __rhs)
      |                 ~~~~~~~~~~~~~~~~^~~~~

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