View difference between Paste ID: d0Ued173 and s0BdikJQ

 expr : expr[ var_name ] '+' ident[ other_var_name ] ( some_action(var_name, other_var_name)) | ident[ third_var ] (some_other_action(third_var))
 
 std::wstring ShiftIdent() {
     auto ident = current_token->codepoints; // for example
     current_token++;
     return ident;
 }
 
 void ShiftPlus() {
     current_token++;
 }
 
 T ShiftExpr() {
     T t;
     switch(current_token->type) {
     case ident:
         auto internal_var = ShiftIdent();
         {
             auto&& third_var = internal_var;
             t = some_other_action(third_var);
         }
         while(true) {
             switch(current_token->type) {
             case '+':
                 ShiftPlus();
                 switch(current_token->type) {
                 case ident:
                     auto&& other_var_name = ShiftIdent();
                     {
                         auto&& var_name = t;
                         t = some_action(var_name, other_var_name));
                     };
                     continue;
                 default:
                     error();
                 }
             case end:
                 break;
             default:
                 error();
             };
         }
         break;
     default:
         error();
     }
     return std::move(t);
 }