blocks|key|2401554|text|不知道keil，但至少在Linux中是一个创建UINT32_C文本的宏。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2401555|正如其他人所提到的，uint32_t是stdint.h中定义为C99的类型。|2401556|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

Don't know about keil, but at least in Linux UINT32_C is a macro to create a uint32_t literal.

And as mentioned by others, uint32_t is a type defined as of C99 in stdint.h.

blocks|key|2401576|text|UINT32_C是一个宏，它定义uint_least32_t类型的整数常数。例如：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2401577|UINT32_C(123)+//+Might+expand+to+123UL+on+system+where+uint_least32_t+is+unsigned+long
++++++++++++++//+or+just+123U,+if+uint_least32_t+is+unsigned+int.|code-block|syntax|javascript|2401578|7.20.4.1最小宽度整数常数的宏|blockquote|2401579|宏INTN_C(value)应展开为与int_leastN_t.类型相对应的整数常量表达式。宏UINTN_C(value)应展开为与uint_leastN_t.类型相对应的整数常量表达式。例如，如果uint_least64_t是unsigned+long+long+int类型的名称，那么UINT64_C(0x123)可以展开为整数常量0x123ULL。|ordered-list-item|BOLD|2401580|因此，在一些罕见的系统上，这个常数有可能超过32位。|2401581|但是，如果您在一个系统中定义了8位2的补码类型的多重(大多数现代系统)，并且存在uint32_t，那么这就创建了32位常量。|2401582|它们都是在stdint.h中定义的，并且自C99以来一直是C标准的一部分。|2401583|entityMap^0|0|8|G|E|0|0|0|1|7|D|1|J|C|1B|8|1O|1|1U|D|2R|E|36|M|40|F|4O|8|0|0|14|8|0|5|8|0^^$0|@$1|2|3|4|5|6|7|Z|8|@$9|10|A|11|B|C]|$9|12|A|13|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|14|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|M|7|15|8|@]|D|@]|E|$]]|$1|N|3|O|5|P|7|16|8|@$9|17|A|18|B|Q]|$9|19|A|1A|B|Q]|$9|1B|A|1C|B|Q]|$9|1D|A|1E|B|Q]|$9|1F|A|1G|B|Q]|$9|1H|A|1I|B|Q]|$9|1J|A|1K|B|C]|$9|1L|A|1M|B|C]|$9|1N|A|1O|B|C]|$9|1P|A|1Q|B|C]]|D|@]|E|$]]|$1|R|3|S|5|6|7|1R|8|@]|D|@]|E|$]]|$1|T|3|U|5|6|7|1S|8|@$9|1T|A|1U|B|C]]|D|@]|E|$]]|$1|V|3|W|5|6|7|1V|8|@$9|1W|A|1X|B|C]]|D|@]|E|$]]|$1|X|3|-4|5|6|7|1Y|8|@]|D|@]|E|$]]]|Y|$]]

<code>UINT32_C</code> is a macro which defines integer constant of type <code>uint_least32_t</code>. For example:

<pre><code>UINT32_C(123) // Might expand to 123UL on system where uint_least32_t is unsigned long
 // or just 123U, if uint_least32_t is unsigned int.
</code></pre>

<blockquote>
 <h3>7.20.4.1 Macros for minimum-width integer constants</h3>
 
 <ol>
 <li>The macro INTN_C(value) shall expand to an integer constant expression
 corresponding to the type int_leastN_t. The macro UINTN_C(value) shall expand
 to an integer constant expression corresponding to the type uint_leastN_t. For
 example, if <code>uint_least64_t</code> is a name for the type <code>unsigned long long int</code>,
 then <code>UINT64_C(0x123)</code> might expand to the integer constant <code>0x123ULL</code>.</li>
 </ol>
</blockquote>

It is thus possible that this constant is more than 32 bits on some rare systems.

But if you are on a system where multiple of 8-bits 2's complement types are defined (most modern systems), and <code>uint32_t</code> exists, then this creates 32-bit constant.

They all are defined in <code>stdint.h</code>, and have been part of the C standard since C99.

blocks|key|2439871|text|它是追加后缀的宏，创建文字，例如#define+UINT32_C(c)+c##UL|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2439872|entityMap^0|G|P|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

It is the macro appending the suffix creating the literal for example <code>#define UINT32_C(c) c##UL</code>

blocks|key|2401685|text|UINT32_C是一个宏，用于编写类型为uint_least32_t的常量。这样的常量适用于初始化uint32_t变量。例如，我在avr-libc中找到了以下定义(这是针对AVR目标的定义，就像一个例子一样)：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2401686|#define+++++UINT32_C(value)+++__CONCAT(value,+UL)|code-block|syntax|javascript|2401687|所以，当你写|2401688|UINT32_C(25)|2401689|它被扩展到|2401690|25UL|2401691|UL是unsigned+long整数常量的后缀。宏很有用，因为uint32_t没有标准的后缀，所以您可以在不知道目标上uint32_t是typedef+(例如unsigned+long+)的情况下使用它。对于其他目标，它将以不同的方式定义。|2401692|entityMap|0|LINK|mutability|MUTABLE|url|http://www.nongnu.org/avr-libc/user-manual/group__avr__stdint.html^0|0|8|K|E|1D|8|1T|8|0|0|0|0|0|0|0|0|2|3|D|V|8|1N|8|1W|7|27|D|0^^$0|@$1|2|3|4|5|6|7|12|8|@$9|13|A|14|B|C]|$9|15|A|16|B|C]|$9|17|A|18|B|C]]|D|@$9|19|A|1A|1|1B]]|E|$]]|$1|F|3|G|5|H|7|1C|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|1D|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|1E|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|1F|8|@]|D|@]|E|$]]|$1|Q|3|R|5|H|7|1G|8|@]|D|@]|E|$I|J]]|$1|S|3|T|5|6|7|1H|8|@$9|1I|A|1J|B|C]|$9|1K|A|1L|B|C]|$9|1M|A|1N|B|C]|$9|1O|A|1P|B|C]|$9|1Q|A|1R|B|C]|$9|1S|A|1T|B|C]]|D|@]|E|$]]|$1|U|3|-4|5|6|7|1U|8|@]|D|@]|E|$]]]|V|$W|$5|X|Y|Z|E|$10|11]]]]

<code>UINT32_C</code> is a macro for writing a constant of type <code>uint_least32_t</code>. Such a constant is suitable e.g. for initializing an <code>uint32_t</code> variable. I found for example the following definition in <a href="http://www.nongnu.org/avr-libc/user-manual/group__avr__stdint.html" rel="noreferrer">avr-libc</a> (this is for the AVR target, just as an example):

<pre><code>#define UINT32_C(value) __CONCAT(value, UL)
</code></pre>

So, when you write

<pre><code>UINT32_C(25)
</code></pre>

it's expanded to

<pre><code>25UL
</code></pre>

<code>UL</code> is the suffix for an <code>unsigned long</code> integer constant. The macro is useful because there is no standard suffix for <code>uint32_t</code>, so you can use it without knowing that on your target, <code>uint32_t</code> is a <code>typedef</code> e.g. for <code>unsigned long</code>. With other targets, it will be defined in a different way.

blocks|key|2439907|text|这些常量的定义如下：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2439908|#define+UINT32_C(value)+(value##UL)|code-block|syntax|javascript|2439909|您只能将常量值作为宏参数，否则它将无法编译。|2439910|UINT32_C(10);+//+compiles

uint32_t+x+=+10;
UINT32_C(x);+//+does+not+compile|2439911|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]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

These constants are defined something like this:

<pre><code>#define UINT32_C(value) (value##UL)
</code></pre>

You can only put constant values as macro argument, otherwise it wont compile.

<pre><code>UINT32_C(10); // compiles

uint32_t x = 10;
UINT32_C(x); // does not compile
</code></pre>

As far as I know the suffix t in uint32_t denote type name but I wonder to know what is the C in UINT32_C and what is the differences?

Difference between UINT32_C and uint32_t

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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据我所知，t在uint32_t中表示type名称，但我想知道UINT32_C中的C是什么，区别是什么？

问UINT32_C与uint32_t的区别
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