Strin Remove the end of the Space function __ function

Equivalent to CString trimleft and TrimRight functions.
String Trimleft (const string& INSTR)
{
String outstr;
outstr = INSTR;
Outstr.erase (0,outstr.find_first_not_of (""));
return outstr;
}

String TrimRight (const string& INSTR)
{
String outstr;
outstr = INSTR;
Outstr.erase (Outstr.find_last_not_of ("") + 1);
return outstr;
}

The role of the find_first_not_of function is to find the position of the first character that is not a space from scratch.
The Find_last_not_of function starts at the end of the search.