c++ - What is the best way to write a loop with no body

Question

I have a function func which returns true or false. Until func returns false, I want to keep calling it. What is the least awkward way to do this?

do {
  // do nothing
} while (func());

or..

while (func());

or..

while (func())
  if (!func())
    break;

All of them look really awkward and unintuitive to me. Is there another solution to this altogether?

Answer 1

I think option B is most commonly used, but you should make it more obvious that you have an empty loop body:

while (func())
  ; // do nothing

or

while (func())  { /* do nothing */ }

As a side note, this looks like some kind of busy waiting. If this is the case, it can and should usually be avoided by using OS-provided synchronization primitives.

Answer 2

我以前写

while (func()) continue;

当我需要一个完整的忙等待循环时（这不是很常见）。关键字使得很难错过意图，并且它被编译掉了。:)

Answer 3

选项 B 的变体：

while (func())
{
    // no-op
}

Answer 4

好吧，第三个做了一些不同的事情——func每次迭代它会调用两次。

我猜你想要第二个，它不会让其他人感到困惑。