[mpls-linux-general] coding style of macros

[nerdboy <ne...@re...>]

here's a macro i came across in the mpls linux code

define INIT_LIST_HEAD(ptr) do { \
        (ptr)->next = (ptr); (ptr)->prev = (ptr); \
} while (0)

at the risk of sounding prude,
why is it that the initialization statements were enclosed in braces with a 
while(0) ?

couldn't it be simply written as 

define INIT_LIST_HEAD(ptr)      (ptr)->next = (ptr); (ptr)->prev = (ptr); 

or does enclosing it in a one time do-while serve any purpose ?

many many thanks in advance
nerd