Function is not a memeber of for a Tree class (CS2039).

[JLBorges]

> MS VS even gives the column number!

Every compiler gives the column number, some even indicate it visually.

For example, with

int main() 
{
   int i = -1 ;
   return i++ + i ;
}

g++ reports:

main.cpp:4:12: warning: operation on 'i' may be undefined [-Wsequence-point]
    4 |    return i++ + i ;
      |           ~^~

clang++ gives a more precise diagnostic:

main.cpp:4:12: warning: unsequenced modification and access to 'i' [-Wunsequenced]
   return i++ + i ;
           ^    ~

http://coliru.stacked-crooked.com/a/547896458aebe9d0