New tools that once you use them, you can't remember how you could live your life without them. They may even not come off!

你使用新工具时，你不可能忘记没有它们你该怎么办。它们甚至不可以掉落！

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Once you have enough of these, you can use them to automatically determine necessary compiler flags and definitions to put in a header file somewhere.

一旦您有了足够的测试程序，您可以用它们来自动确定必需的编译标记和定义，以将它们放到头文件的某个地方。

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We also included some basic techniques you can probably use in every project you are developing, but which are hard to find once you need them.

这里还将包括一些你在日常的项目开发中经常用到的，但是你需要的时候又比较难以找到的一些基本技巧。

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"Once you create these tools, it's very tempting to use them, " says Jonathan Zittrain, a Harvard Law professor.

FORBES: Spotting Evil

Once you have a handful of clear, high-leverage strategies, you can use them as a filter to decide what to do.

FORBES

Once you have your list, use the app to tick off things as you pack them, or e-mail the list to other family members.

BBC: Seven trusted family travel apps