阅读C库的套接字接口的代码,我发现了这个:
/* Types of sockets. */
enum __socket_type
{
SOCK_STREAM = 1, /* Sequenced, reliable, connection-based
byte streams. */
#define SOCK_STREAM SOCK_STREAM
SOCK_DGRAM = 2, /* Connectionless, unreliable datagrams
of fixed maximum length. */
#define SOCK_DGRAM SOCK_DGRAM
...
这个"成语"遍及bits/socket.h.我只是好奇,那些宏的目的是什么？