blocks|key|1288539|text|在C%2B%2B11中，您有原始的字符串文字。有点像这里-shell和脚本语言中的文本，如Python、Perl和Ruby。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1288540|const+char+*+vogon_poem+=+R"V0G0N(
+++++++++++++O+freddled+gruntbuggly+thy+micturations+are+to+me
+++++++++++++++++As+plured+gabbleblochits+on+a+lurgid+bee.
++++++++++++++Groop,+I+implore+thee+my+foonting+turlingdromes.+++
+++++++++++And+hooptiously+drangle+me+with+crinkly+bindlewurdles,
Or+I+will+rend+thee+in+the+gobberwarts+with+my+blurlecruncheon,+see+if+I+don't.

++++++++++++++++(by+Prostetnic+Vogon+Jeltz;+see+p.+56/57)
)V0G0N";|code-block|syntax|javascript|1288541|字符串中的所有空格、缩进和换行符都将保留。|1288542|它们也可以是utf-8%7C16%7C32或wchar_t+(带有常用的前缀)。|1288543|我应该指出的是，转义序列V0G0N在这里实际上并不需要。它的存在将允许将)“放入字符串中。|1288544|++++++++++++++++"(by+Prostetnic+Vogon+Jeltz;+see+p.+56/57)"|1288545|(注意额外的引号)，上面的字符串仍然是正确的。否则我也可以用|1288546|const+char+*+vogon_poem+=+R"(+...+)";|1288547|仍然需要引号内的花括号。|1288548|entityMap^0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Y|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|Z|8|@]|9|@]|A|$]]|$1|K|3|L|5|6|7|10|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|11|8|@]|9|@]|A|$E|F]]|$1|O|3|P|5|6|7|12|8|@]|9|@]|A|$]]|$1|Q|3|R|5|D|7|13|8|@]|9|@]|A|$E|F]]|$1|S|3|T|5|6|7|14|8|@]|9|@]|A|$]]|$1|U|3|-4|5|6|7|15|8|@]|9|@]|A|$]]]|V|$]]

In C++11 you have raw string literals. Sort of like here-text in shells and script languages like Python and Perl and Ruby.

<pre><code>const char * vogon_poem = R"V0G0N(
 O freddled gruntbuggly thy micturations are to me
 As plured gabbleblochits on a lurgid bee.
 Groop, I implore thee my foonting turlingdromes. 
 And hooptiously drangle me with crinkly bindlewurdles,
Or I will rend thee in the gobberwarts with my blurlecruncheon, see if I don't.

 (by Prostetnic Vogon Jeltz; see p. 56/57)
)V0G0N";
</code></pre>

All the spaces and indentation and the newlines in the string are preserved.

These can also be utf-8|16|32 or wchar_t (with the usual prefixes).

I should point out that the escape sequence, V0G0N, is not actually needed here. Its presence would allow putting )" inside the string. In other words, I could have put

<pre><code> "(by Prostetnic Vogon Jeltz; see p. 56/57)"
</code></pre>

(note extra quotes) and the string above would still be correct. Otherwise I could just as well have used

<pre><code>const char * vogon_poem = R"( ... )";
</code></pre>

The parens just inside the quotes are still needed.

blocks|key|1503458|text|您还可以执行以下操作：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1503459|const+char+*longString+=+R""""(
This+is+
a+very+
long+
string
)"""";|code-block|syntax|javascript|1503460|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

You can also do this:

<pre><code>const char *longString = R""""(
This is 
a very 
long 
string
)"""";
</code></pre>

blocks|key|1288579|text|#define+MULTILINE(...)+#__VA_ARGS__|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1288580|消耗括号之间的所有内容。|1288581|将任意数量的连续空格字符替换为单个空格。|1288582|entityMap^0|0|Z|0|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@$9|M|A|N|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|O|8|@]|D|@]|E|$]]|$1|H|3|I|5|6|7|P|8|@]|D|@]|E|$]]|$1|J|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|K|$]]

<code>#define MULTILINE(...) #__VA_ARGS__</code> 
Consumes everything between the parentheses. 
Replaces any number of consecutive whitespace characters by a single space.

blocks|key|1503272|text|你可以这样做：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1503273|const+char+*text+=+"This+is+my+string+it+is+"
+++++"very+long";|code-block|syntax|javascript|1503274|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

You can just do this:

<pre><code>const char *text = "This is my string it is "
 "very long";
</code></pre>

blocks|key|1503402|text|为了澄清@emsr在@unwind的答案中的评论，如果没有足够幸运的C%2B%2B11编译器(比如GCC+4.2.1)，并且想要在字符串(+char+*或类string)中嵌入换行符，可以这样写：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1503403|const+char+*text+=
++"This+text+is+pretty+long,+but+will+be\n"
++"concatenated+into+just+a+single+string.\n"
++"The+disadvantage+is+that+you+have+to+quote\n"
++"each+part,+and+newlines+must+be+literal+as\n"
++"usual.";|code-block|syntax|javascript|1503404|很明显，这是真的，但当我第一次读到这篇文章时，@emsr的简短评论并没有引起我的注意，所以我不得不自己去发现这一点。希望我已经为其他人节省了几分钟。|1503405|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Just to elucidate a bit on @emsr's comment in @unwind's answer, if one is not fortunate enough to have a C++11 compiler (say GCC 4.2.1), and one wants to embed the newlines in the string (either char * or class string), one can write something like this:

<pre><code>const char *text =
 "This text is pretty long, but will be\n"
 "concatenated into just a single string.\n"
 "The disadvantage is that you have to quote\n"
 "each part, and newlines must be literal as\n"
 "usual.";
</code></pre>

Very obvious, true, but @emsr's short comment didn't jump out at me when I read this the first time, so I had to discover this for myself. Hopefully, I've saved someone else a few minutes.

blocks|key|1503440|text|因为一盎司的经验胜过一吨的理论，所以我尝试了MULTILINE的一个小测试程序|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1503441|#define+MULTILINE(...)+#__VA_ARGS__

const+char+*mstr[]+=
{
++++MULTILINE(1,+2,+3),+++++++//+"1,+2,+3"
++++MULTILINE(1,2,3),+++++++++//+"1,2,3"
++++MULTILINE(1+,+2+,+3),+++++//+"1+,+2+,+3"
++++MULTILINE(+1+,+2+,+3+),+++//+"1+,+2+,+3"
++++MULTILINE((1,++2,++3)),+++//+"(1,++2,++3)"
++++MULTILINE(1
++++++++++++++2
++++++++++++++3),+++++++++++++//+"1+2+3"
++++MULTILINE(1\n2\n3\n),+++++//+"1\n2\n3\n"
++++MULTILINE(1\n
++++++++++++++2\n
++++++++++++++3\n),+++++++++++//+"1\n+2\n+3\n"
++++MULTILINE(1,+"2"+\3)++++++//+"1,+\"2\"+\3"
};|code-block|syntax|javascript|1503442|使用cpp+-P+-std=c%2B%2B11+filename编译此片段以进行重现。|1503443|#__VA_ARGS__背后的诀窍是__VA_ARGS__不处理逗号分隔符。所以你可以把它传递给字符串化操作符。前导空格和尾随空格被修剪掉，单词之间的空格(包括换行符)被压缩为一个空格。括号需要对齐。我认为这些缺点解释了为什么尽管使用#__VA_ARGS__，C%2B%2B11的设计者仍然认为需要原始的字符串文字。|1503444|entityMap^0|M|9|0|0|2|Q|0|0|C|I|B|39|C|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@]|E|$]]|$1|M|3|N|5|6|7|X|8|@$9|Y|A|Z|B|C]|$9|10|A|11|B|C]|$9|12|A|13|B|C]]|D|@]|E|$]]|$1|O|3|-4|5|6|7|14|8|@]|D|@]|E|$]]]|P|$]]

Since an ounce of experience is worth a ton of theory, I tried a little test program for <code>MULTILINE</code>:

<pre class="lang-c prettyprint-override"><code>#define MULTILINE(...) #__VA_ARGS__

const char *mstr[] =
{
 MULTILINE(1, 2, 3), // "1, 2, 3"
 MULTILINE(1,2,3), // "1,2,3"
 MULTILINE(1 , 2 , 3), // "1 , 2 , 3"
 MULTILINE( 1 , 2 , 3 ), // "1 , 2 , 3"
 MULTILINE((1, 2, 3)), // "(1, 2, 3)"
 MULTILINE(1
 2
 3), // "1 2 3"
 MULTILINE(1\n2\n3\n), // "1\n2\n3\n"
 MULTILINE(1\n
 2\n
 3\n), // "1\n 2\n 3\n"
 MULTILINE(1, "2" \3) // "1, \"2\" \3"
};
</code></pre>

Compile this fragment with <code>cpp -P -std=c++11 filename</code> to reproduce.

The trick behind <code>#__VA_ARGS__</code> is that <code>__VA_ARGS__</code> does not process the comma separator. So you can pass it to the stringizing operator. Leading and trailing spaces are trimmed, and spaces (including newlines) between words are compressed to a single space then. Parentheses need to be balanced. I think these shortcomings explain why the designers of C++11, despite <code>#__VA_ARGS__</code>, saw the need for raw string literals.

blocks|key|1288704|text|//+C%2B%2B11.+
std::string+index_html=R"html(
<!DOCTYPE+html>
<html+lang="en">
<head>
++++<meta+charset="UTF-8">
++++<title>VIPSDK+MONITOR</title>
++++<meta+http-equiv="refresh"+content="10">
</head>
<style+type="text/css">
</style>
</html>
)html";|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1288705|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>// C++11. 
std::string index_html=R"html(
&lt;!DOCTYPE html&gt;
&lt;html lang="en"&gt;
&lt;head&gt;
 &lt;meta charset="UTF-8"&gt;
 &lt;title&gt;VIPSDK MONITOR&lt;/title&gt;
 &lt;meta http-equiv="refresh" content="10"&gt;
&lt;/head&gt;
&lt;style type="text/css"&gt;
&lt;/style&gt;
&lt;/html&gt;
)html";
</code></pre>

blocks|key|1288770|text|选项1.使用boost库，您可以按如下方式声明字符串|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1288771|const+boost::string_view+helpText+=+"This+is+very+long+help+text.\n"
++++++"Also+more+text+is+here\n"
++++++"And+here\n"

//+Pass+help+text+here
setHelpText(helpText);|code-block|syntax|javascript|1288772|选项2.如果boost在您的项目中不可用，您可以在现代C%2B%2B中使用std::string_view()。|1288773|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Option 1. Using boost library, you can declare the string as below

<pre><code>const boost::string_view helpText = "This is very long help text.\n"
 "Also more text is here\n"
 "And here\n"

// Pass help text here
setHelpText(helpText);
</code></pre>

Option 2. If boost is not available in your project, you can use std::string_view() in modern C++.

Is there any way to have multi-line plain-text, constant literals in C++, à la Perl? Maybe some parsing trick with <code>#include</code>ing a file? I can't think of one, but boy, that would be nice. I know it'll be in C++0x.

C++ multiline string literal

编译器

Python

Perl

有没有办法在C++中使用多行纯文本，常量文字，就像Perl一样？也许是#include在文件中的一些解析技巧？我想不出一个，但是天哪，那太好了。我知道它会在C++0x里。

问C++多行字符串文字
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