blocks|key|354838|text|如果你需要使用一定长度的整数，你可能应该使用一些与平台无关的头来帮助你。Boost是一个值得关注的好地方。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|354839|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

If you need to use integers of certain length, you probably should use some platform independent headers to help you. Boost is a good place to look at.

blocks|key|3350500|text|这篇关于MSDN的文章引用了许多类型别名(在Windows上可用)，它们在宽度方面更加明确：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3350501|http://msdn.microsoft.com/en-us/library/aa505945.aspx|offset|length|3350502|例如，虽然可以使用ULONGLONG引用64位无符号整数值，但也可以使用UINT64。(尤龙和UINT32也是如此。)也许这些会更清楚一些？|3350503|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|1H|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@$D|Q|E|R|1|S]]|A|$]]|$1|F|3|G|5|6|7|T|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|U|8|@]|9|@]|A|$]]]|I|$J|$5|K|L|M|A|$N|C]]]]

This article on MSDN references a number of type aliases (available on Windows) that are a bit more explicit with respect to their width:

<a href="http://msdn.microsoft.com/en-us/library/aa505945.aspx" rel="nofollow noreferrer">http://msdn.microsoft.com/en-us/library/aa505945.aspx</a>

For instance, although you can use ULONGLONG to reference a 64-bit unsigned integral value, you can also use UINT64. (The same goes for ULONG and UINT32.) Perhaps these will be a bit clearer?

blocks|key|3350527|text|了解您的编译器/平台的最简单方法是：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3350528|#include+<iostream>

int+main()+{
++std::cout+<<+sizeof(long)*8+<<+std::endl;
}|code-block|syntax|javascript|3350529|8的乘法是从字节中得到位。|3350530|当您需要特定大小时，使用某个预定义类型的库通常是最容易的。如果这不是您想要的，您可以使用autoconf软件执行通常发生的操作，并让配置系统为所需的大小确定正确的类型。|3350531|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|P|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

The easiest way to get to know it for your compiler/platform:

<pre><code>#include &lt;iostream&gt;

int main() {
 std::cout &lt;&lt; sizeof(long)*8 &lt;&lt; std::endl;
}
</code></pre>

Themultiplication by 8 is to get bits from bytes.

When you need a particular size, it is often easiest to use one of the predefined types of a library. If that is undesirable, you can do what often happens with autoconf software and have the configuration system determine the right type for the needed size.

blocks|key|3350562|text|微软还为与指针大小相同的整数定义了UINT_PTR和INT_PTR。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3350563|这是一个list+of+Microsoft+specific+types+-它是他们的驱动程序参考的一部分，但我相信它对于一般编程也是有效的。|offset|length|3350564|entityMap|0|LINK|mutability|MUTABLE|url|http://msdn.microsoft.com/en-us/library/ff564619.aspx^0|0|4|W|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|O|8|@]|9|@$D|P|E|Q|1|R]]|A|$]]|$1|F|3|-4|5|6|7|S|8|@]|9|@]|A|$]]]|G|$H|$5|I|J|K|A|$L|M]]]]

Microsoft has also defined UINT_PTR and INT_PTR for integers that are the same size as a pointer.

Here is a <a href="http://msdn.microsoft.com/en-us/library/ff564619.aspx" rel="nofollow noreferrer">list of Microsoft specific types</a> - it's part of their driver reference, but I believe it's valid for general programming as well.

blocks|key|3137890|text|在Unix世界中，64位平台的整数和指针的大小有几种可能的安排。使用最广泛的两个是ILP64+(实际上，这方面的例子很少；Cray就是其中之一)和LP64+(几乎所有其他东西都是这样)。这些首字母缩写来自于“int，long，pointers+64-bit”和“long，pointers+are+64-bit”。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3137891|Type+++++++++++ILP64+++LP64+++LLP64
char++++++++++++++8++++++8+++++++8
short++++++++++++16+++++16++++++16
int++++++++++++++64+++++32++++++32
long+++++++++++++64+++++64++++++32
long+long++++++++64+++++64++++++64
pointer++++++++++64+++++64++++++64|code-block|syntax|javascript|3137892|ILP64系统被抛弃，取而代之的是LP64+(也就是说，根据Aspen小组的建议，几乎所有后来的进入者都使用LP64；只有具有64位操作历史的系统才使用不同的方案)。所有现代64位Unix系统都使用LP64。Linux和MacOS都是现代的64位系统。|offset|length|3137893|微软使用了一种不同的方案来过渡到64位:+LLP64+(“长长的指针是64位的”)。这样做的好处是，32位软件无需更改即可重新编译。它的缺点是不同于其他任何人所做的事情，并且还需要修改代码以利用64位容量。总是有必要进行修订；它只是与Unix平台上需要的修订集不同而已。|3137894|如果您围绕平台中立的整数类型名称设计软件，则可能使用C99+<inttypes.h>标头，当这些类型在平台上可用时，该标头提供有符号(列出)和无符号(未列出；前缀为'u')：|style|CODE|3137895|3137896|int8_t+-8位integers|unordered-list-item|3137897|int16_t+-16位integers|3137898|int32_t+-32位integers|3137899|int64_t+-64位integers|3137900|uintptr_t+-大到足以容纳pointers|3137901|intmax_t的无符号整数-平台上整数的最大值(可能大于int64_t)|3137902|3137903|然后，您可以在重要的地方使用这些类型编写应用程序，并非常小心地使用系统类型(这可能是不同的)。有一种intptr_t类型--一种用于保存指针的带符号整数类型；您应该计划不使用它，或者只将它用作两个uintptr_t值(ptrdiff_t)的减法结果。|3137904|但是，正如问题指出的那样(难以置信)，64位机器上整数数据类型的大小有不同的系统。习惯它；这个世界不会改变。|3137905|entityMap|0|LINK|mutability|MUTABLE|url|http://www.unix.org/version2/whatsnew/lp64_wp.html^0|0|0|H|4|0|0|0|U|C|0|0|0|6|0|0|7|0|0|7|0|0|7|0|0|9|0|0|8|T|7|0|0|1E|8|2Q|9|31|9|0|0^^$0|@$1|2|3|4|5|6|7|1H|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|1I|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|1J|8|@]|9|@$I|1K|J|1L|1|1M]]|A|$]]|$1|K|3|L|5|6|7|1N|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|1O|8|@$I|1P|J|1Q|O|P]]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|1R|8|@]|9|@]|A|$]]|$1|R|3|S|5|T|7|1S|8|@$I|1T|J|1U|O|P]]|9|@]|A|$]]|$1|U|3|V|5|T|7|1V|8|@$I|1W|J|1X|O|P]]|9|@]|A|$]]|$1|W|3|X|5|T|7|1Y|8|@$I|1Z|J|20|O|P]]|9|@]|A|$]]|$1|Y|3|Z|5|T|7|21|8|@$I|22|J|23|O|P]]|9|@]|A|$]]|$1|10|3|11|5|T|7|24|8|@$I|25|J|26|O|P]]|9|@]|A|$]]|$1|12|3|13|5|T|7|27|8|@$I|28|J|29|O|P]|$I|2A|J|2B|O|P]]|9|@]|A|$]]|$1|14|3|-4|5|6|7|2C|8|@]|9|@]|A|$]]|$1|15|3|16|5|6|7|2D|8|@$I|2E|J|2F|O|P]|$I|2G|J|2H|O|P]|$I|2I|J|2J|O|P]]|9|@]|A|$]]|$1|17|3|18|5|6|7|2K|8|@]|9|@]|A|$]]|$1|19|3|-4|5|6|7|2L|8|@]|9|@]|A|$]]]|1A|$1B|$5|1C|1D|1E|A|$1F|1G]]]]

In the Unix world, there were a few possible arrangements for the sizes of integers and pointers for 64-bit platforms. The two mostly widely used were ILP64 (actually, only a very few examples of this; Cray was one such) and LP64 (for almost everything else). The acronynms come from 'int, long, pointers are 64-bit' and 'long, pointers are 64-bit'.

<pre><code>Type ILP64 LP64 LLP64
char 8 8 8
short 16 16 16
int 64 32 32
long 64 64 32
long long 64 64 64
pointer 64 64 64
</code></pre>

The ILP64 system was abandoned in favour of <a href="http://www.unix.org/version2/whatsnew/lp64_wp.html" rel="noreferrer">LP64</a> (that is, almost all later entrants used LP64, based on the recommendations of the Aspen group; only systems with a long heritage of 64-bit operation use a different scheme). All modern 64-bit Unix systems use LP64. MacOS X and Linux are both modern 64-bit systems.

Microsoft uses a different scheme for transitioning to 64-bit: LLP64 ('long long, pointers are 64-bit'). This has the merit of meaning that 32-bit software can be recompiled without change. It has the demerit of being different from what everyone else does, and also requires code to be revised to exploit 64-bit capacities. There always was revision necessary; it was just a different set of revisions from the ones needed on Unix platforms.

If you design your software around platform-neutral integer type names, probably using the C99 <code>&lt;inttypes.h&gt;</code> header, which, when the types are available on the platform, provides, in signed (listed) and unsigned (not listed; prefix with 'u'):

<ul>
<li><code>int8_t</code> - 8-bit integers</li>
<li><code>int16_t</code> - 16-bit integers</li>
<li><code>int32_t</code> - 32-bit integers</li>
<li><code>int64_t</code> - 64-bit integers</li>
<li><code>uintptr_t</code> - unsigned integers big enough to hold pointers</li>
<li><code>intmax_t</code> - biggest size of integer on the platform (might be larger than <code>int64_t</code>)</li>
</ul>

You can then code your application using these types where it matters, and being very careful with system types (which might be different). There is an <code>intptr_t</code> type - a signed integer type for holding pointers; you should plan on not using it, or only using it as the result of a subtraction of two <code>uintptr_t</code> values (<code>ptrdiff_t</code>).

But, as the question points out (in disbelief), there are different systems for the sizes of the integer data types on 64-bit machines. Get used to it; the world isn't going to change.

blocks|key|357622|text|在Windows平台上，long的位数是32位(4字节)。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|357623|您可以使用sizeof(long)检查这一点。|357624|entityMap|0|LINK|mutability|MUTABLE|url|https://godbolt.org/z/vCicB4^0|C|4|0|5|C|5|C|0|0^^$0|@$1|2|3|4|5|6|7|P|8|@$9|Q|A|R|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@$9|V|A|W|1|X]]|E|$]]|$1|H|3|-4|5|6|7|Y|8|@]|D|@]|E|$]]]|I|$J|$5|K|L|M|E|$N|O]]]]

The size in bits of <code>long</code> on Windows platforms is 32 bits (4 bytes).

You can check this using <a href="https://godbolt.org/z/vCicB4" rel="nofollow noreferrer"><code>sizeof(long)</code></a>.

Not to long ago, someone told me that <code>long</code> are not 64 bits on 64 bit machines and I should always use <code>int</code>. This did not make sense to me. I have seen docs (such as the one on Apple's official site) say that <code>long</code> are indeed 64 bits when compiling for a 64-bit CPU. I looked up what it was on 64-bit Windows and found 

<blockquote>
 <ul>
 <li>Windows: <code>long</code> and <code>int</code> remain 32-bit in length, and special new data types
 are defined for 64-bit integers.</li>
 </ul>
</blockquote>

(from <a href="http://web.archive.org/web/20080117221414/http://www.intel.com:80/cd/ids/developer/asmo-na/eng/197664.htm?page=2" rel="noreferrer">http://www.intel.com/cd/ids/developer/asmo-na/eng/197664.htm?page=2</a>)

What should I use? Should I define something like <code>uw</code>, <code>sw</code> ((un)signed width) as a <code>long</code> if not on Windows, and otherwise do a check on the target CPU bitsize?

What is the bit size of long on 64-bit Windows?

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不久前，有人告诉我，64位机器上的long不是64位的，我应该一直使用int。这对我来说是没有意义的。我见过一些文档(比如苹果官网上的那个)说，在编译64位long时，它确实是64位的。我在64位Windows上查了一下，发现窗口：long和int的长度保持为32位，并且为64位整数定义了特殊的新数据类型。(来自)我应...

问在64位Windows上，long的位大小是多少？
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问在64位Windows上，long的位大小是多少？
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