typeof(3) - NetBSD Manual Pages

TYPEOF(3)               NetBSD Library Functions Manual              TYPEOF(3)


NAME

     typeof -- GNU extension for type of an expression


SYNOPSIS

     type
     typeof(expression);


DESCRIPTION

     The typeof() construct can be used to obtain the type of an expression.
     The syntax is comparable to that of sizeof(), but semantically typeof()
     operates like a type name defined with typedef.


EXAMPLES

     The following is a typical example of a type-generic macro:

           #define MAX(a, b) ({            \
                   typeof(a) _a = (a);     \
                   typeof(b) _b = (b);     \
                   _a > _b ? _a : _b;      \
           })


SEE ALSO

     gcc(1), __alignof__(3), attribute(3), offsetof(3)


CAVEATS

     The typeof() construct is a non-standard, compiler-specific extension.

NetBSD 10.99                   December 19, 2010                  NetBSD 10.99