Yang Zhang wrote: > Hi, what's the difference among inline vs. __inline vs. __inline__ vs. > __attribute__((always_inline))? I couldn't find __inline or __inline__ > in the documentation - are we not meant to use them? Thanks! The keywords with leading underscores are for when you must write ANSI C89 compatible code: <http://gcc.gnu.org/onlinedocs/gcc/Alternate-Keywords.html>. There is no semantic difference. The always_inline attribute forces inlining when optimization is not enabled, where it would normally not be done: <http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html#index-g_t_0040code_007balways_005finline_007d-function-attribute-2092> Brian
