A function call is an expression containing the function name followed by the function call operator, (). If the function has been defined to receive parameters, the values that are to be sent into the function are listed inside the parentheses of the function call operator. The argument list can contain any number of expressions separated by commas. The argument list can also be empty.
The type of a function call expression is the return type of the function. This type can either be a complete type, a reference type, or the type void.
A function call is always an rvalue.
A function
call belongs to one of the following value categories depending on
the result type of the function:- An lvalue if the result type is an lvalue reference type
or an rvalue
reference to a function type
- An xvalue if the result type is an rvalue reference to an
object type
- A (prvalue) rvalue in other cases
Here
are some examples of the function call operator:
stub()
overdue(account, date, amount)
notify(name, date + 5)
report(error, time, date, ++num)The order of evaluation
for function call arguments is not specified. In the following example:
method(sample1, batch.process--, batch.process);