Typedef declaration

// simple typedef
typedef unsigned long ulong;
 
// the following two objects have the same type
unsigned long l1;
ulong l2;
 
// more complicated typedef
typedef int int_t, *intp_t, (&fp)(int, ulong), arr_t[10];
 
// the following two objects have the same type
int a1[10];
arr_t a2;
 
// common C idiom to avoid having to write "struct S"
typedef struct {int a; int b;} S;
 
// the following two objects have the same type
struct {int a; int b;} s1;
S s2;
 
// error: conflicting type specifier
// typedef static unsigned int uint;
 
// std::add_const, like many other metafunctions, use member typedefs
template< class T>
struct add_const {
    typedef const T type;
};