The 64-bit return value from sizeof in the following statement is truncated to 32-bits when assigned to bufferSize.
在下面这条语句中，在对 bufferSize 进行赋值时，从sizeof返回的 64 位值被截断成了 32 位。
This request asks for sizeof(data) bytes of data copied from the address in main memory denoted by argp to be copied into the object data.
这个请求会要求将sizeof(data)字节的数据从 argp所指向的主存地址处拷贝到 data 对象中。
This structure has the useful property that if you allocate space for (sizeof(struct header) + 10) bytes, you can treat data as being an array of 10 bytes.
这种结构体的有用之处在于，如果您分配 (sizeof(structheader) +10)字节的空间，您可以像处理一个 10 字节的数组一样来处理数据。
A typeof-construct can be used anywhere a typedef name could be used. For example, you can use it in a declaration, in a cast, or inside of sizeof or typeof.
typeof能被用在任何需要引用类型名的情况下，比如你可以用在声明、显示类型转换（cast）或是在sizeof和typeof内使用。
If you can reasonably conclude that a test is unnecessary (for instance, even machines with bytes larger than 8 bits are still required to have sizeof (char) be 1), you can omit the test entirely.
如果您确认某一个测试是没有必要的(例如，即使机器字节多于8位也仍需要使size of (char)为1)，您可以完全不去进行这个测试。
If you can reasonably conclude that a test is unnecessary (for instance, even machines with bytes larger than 8 bits are still required to have sizeof (char) be 1), you can omit the test entirely.
如果您确认某一个测试是没有必要的(例如，即使机器字节多于8位也仍需要使size of (char)为1)，您可以完全不去进行这个测试。
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