The debugger accepts all valid C/C++ expressions except from assignment operators such as =, +=, −=, etc., prefix and postfix increment and decrement operators ++ and --, the ? : operator and function calls.
Symbols are names which are defined within the target program (for example, variables or procedure names). Depending on their scope, they may not be visible all the time.
SET WATCHPOINT AT call_by_value !symbol: call_by_value SET BREAKPOINT AT main !symbol: main