If the method on the server-side component has a non-void return value, that value is passed into the callback function as its only argument.
如果服务器端组件上的方法具有非空返回值，该值就会作为其惟一的实参传递进此回调函数。
If we had added a getValue method to class Leaf, we would either have to return some sort of flag value indicating that the method application is non-sensical or actually throw an exception.
如果我们已经向Leaf类添加了getValue方法，我们要么是不得不返回一些类型的标志值表明此方法应用是无意义的，要么是实际抛出一个异常。
Test programs generally use the standard Unix conventions: they return 0 in the event of a successful run and some non-zero value in the event of failure.
测试程序遵循标准的Unix习惯：如果测试通过则返回值为0，如果失败则返回一个非0 值。
And you should never unlock a mutex that you don't hold a lock for (otherwise, the pthread_mutex_unlock call will fail with a non-zero EPERM return value).
并且绝对不要对您未保持锁的互斥对象进行解锁操作(否则，pthread _ mutex_unlock调用将失败并带一个非零的eperm返回值)。
If the return type is non-nullable, the default CLR value for the type is returned.
如果返回类型可以为非空型，则返回类型的默认clr值。
If the return type is non-nullable, the default CLR value for the type is returned.
如果返回类型可以为非空型，则返回类型的默认clr值。
应用推荐