variable.c:1651
void
rb_cv_set(klass, name, val)
    VALUE klass;
    const char *name;
    VALUE val;
{
    ID id = rb_intern(name);
    if (!rb_is_class_id(id)) {
	rb_name_error(id, "wrong class variable name %s", name);
    }
    rb_cvar_set(klass, id, val, Qfalse);
}
