Scm_PromiseClass 2438 src/gauche.h   SCM_CLASS_DECL(Scm_PromiseClass);
Scm_PromiseClass 2439 src/gauche.h   #define SCM_CLASS_PROMISE           (&Scm_PromiseClass)
Scm_PromiseClass   90 src/promise.c  SCM_DEFINE_BUILTIN_CLASS_SIMPLE(Scm_PromiseClass, promise_print);