rb_hash_delete_if  980 ext/dbm/dbm.c      return rb_hash_delete_if(fdbm_to_hash(obj));
rb_hash_delete_if 1224 ext/gdbm/gdbm.c     return rb_hash_delete_if(fgdbm_to_hash(obj));
rb_hash_delete_if 1012 ext/sdbm/init.c     return rb_hash_delete_if(fsdbm_to_hash(obj));
rb_hash_delete_if 4028 hash.c             return rb_hash_delete_if(env_to_hash());
rb_hash_delete_if 4306 hash.c             rb_define_method(rb_cHash,"delete_if", rb_hash_delete_if, 0);
rb_hash_delete_if  519 include/ruby/intern.h VALUE rb_hash_delete_if(VALUE);