type va_arg ( va_list ap, type )
Retrieve next argument
This macro expands to an expression that has the type type and the value of the next argument in the variable arguments list.
The next call to this macro will expand to the following argument in the same order as passed to the function.
Notice that va_arg cannot determine the actual type of the argument passed to the function, but uses whatever type is passed as the type macro argument as its type.
Notice also that va_arg does not determine either whether the retrieved argument is the last argument passed to the function (or even if it is an element past the end of that list). The function should be designed in such a way that the amount of parameters can be inferred in some way by the values of either the named parameters or the additional arguments already read.
Object of type va_list with information about the additional arguments an their retrieval state. This object shall have been initialized by an initial call to va_start before the first call to va_arg.
A type name. This type name is used as the type of the expression this macro expands to (i.e., its return type).
For a type expression to be suitable for its use with va_arg it must be such that when an asterisk (*) would be appended to its right the resulting expression would be a valid pointer type to a type object.
Returns the next additional argument as an expression of type type.