only_if_constant 148 thread.c #define only_if_constant(expr, notconst) __builtin_choose_expr(__builtin_constant_p(expr), (expr), (notconst)) only_if_constant 150 thread.c #define only_if_constant(expr, notconst) (__builtin_constant_p(expr) ? (expr) : (notconst)) only_if_constant 153 thread.c #define only_if_constant(expr, notconst) notconst