我可以放心地UInt32的存储NSUInteger？ [英] Can I safely store UInt32 to NSUInteger?

问题描述

在标题中，定义如下：

#if __LP64__ || (TARGET_OS_EMBEDDED && !TARGET_OS_IPHONE) || TARGET_OS_WIN32 || NS_BUILD_32_LIKE_64
typedef long NSInteger;
typedef unsigned long NSUInteger;
#else
typedef int NSInteger;
typedef unsigned int NSUInteger;
#endif

也是如此没有问题，到NSUInteger（一个unsigned int）的UInt32的配合？哪里是UInt32的和unsigned int的区别？

So does an UInt32 fit without problems into an NSUInteger (an unsigned int)? Where's the difference between UInt32 and unsigned int?

和我假设一个unsigned long比一个unsigned int更大？

And I assume that an unsigned long is bigger than an unsigned int?

推荐答案

我想一个 UInt32的和 unsigned int类型之间的唯一区别是一个 UInt32的保证是32位长，而一个 unsigned int类型在技术上可能是较短如果你正在运行的（比如说）＆LT; 32位操作系统。

I suppose the only difference between a UInt32 and an unsigned int is that a UInt32 is guaranteed to be 32 bits long, whereas an unsigned int technically could be shorter if you were running (say) on a < 32-bit operating system.

不过，鉴于苹果和iPhone都至少有32位系统，它的安全使用 unsigned int类型， UInt32的和 NSUInteger 合理互换。这里唯一的不同是， NSUInteger 可能是64位长（在Mac上，为x86_64的编译时）。

However, given that the Mac and the iPhone are both at least 32-bit systems, it's safe to use unsigned int, UInt32, and NSUInteger reasonably interchangeably. The only difference here is that a NSUInteger might be 64 bits long (on the Mac, when compiling for x86_64).

至于你的问题无符号长与 unsigned int类型， UInt32的的typedef定义一个无符号长，再次表明它是安全的交替使用。一个无符号长是保证至少大如 unsigned int类型。

As for your question of unsigned long versus unsigned int, UInt32 is typedef'd to an unsigned long, again indicating that it's safe to use interchangeably. An unsigned long is guaranteed to be at least as big as an unsigned int.

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