let old = refCount() let new do { if (checkZero) { return } new = old + 1 } while ( CAS (old, new) ) ↑シンプルにこういう形ですよ (edited)let old = refCount() let new do { if (checkZero) { return } new = old + 1 } while ( CAS (old, new) ) ↑シンプルにこういう形ですよ (edited)