blocks|key|3043812|text|作为C%2B%2B标准的一部分，您可以使用一些预定义的宏。C%2B%2B标准的第16.8节特别定义了__LINE__宏。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3043813|3043814|+__LINE__**当前源代码行的行号(十进制常量)。|blockquote|BOLD|3043815|3043816|__FILE__**:源文件的假定名称(字符串文字)。|3043817|__DATE__**源文件的翻译日期(字符串...)|3043818|__TIME__**:源文件的翻译时间(字符串...)|3043819|__STDC__**是否预定义了__STDC__|3043820|__cplusplus**:在编译C+%2B%2B翻译单元时，名称__cplusplus被定义为值199711L|3043821|3043822|所以你的代码应该是：|3043823|if(!Logical)
++printf("Not+logical+value+at+line+number+%25d+\n",__LINE__);|code-block|syntax|javascript|3043824|entityMap^0|16|8|0|0|1|R|1|8|0|0|0|8|9|2|0|0|Q|0|8|0|0|8|9|2|0|0|O|0|8|G|8|0|0|B|T|B|C|2|0|0|0|0^^$0|@$1|2|3|4|5|6|7|15|8|@$9|16|A|17|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|18|8|@]|D|@]|E|$]]|$1|G|3|H|5|I|7|19|8|@$9|1A|A|1B|B|J]|$9|1C|A|1D|B|C]]|D|@]|E|$]]|$1|K|3|-4|5|6|7|1E|8|@]|D|@]|E|$]]|$1|L|3|M|5|6|7|1F|8|@$9|1G|A|1H|B|C]|$9|1I|A|1J|B|J]]|D|@]|E|$]]|$1|N|3|O|5|6|7|1K|8|@$9|1L|A|1M|B|J]|$9|1N|A|1O|B|C]]|D|@]|E|$]]|$1|P|3|Q|5|6|7|1P|8|@$9|1Q|A|1R|B|C]|$9|1S|A|1T|B|J]]|D|@]|E|$]]|$1|R|3|S|5|6|7|1U|8|@$9|1V|A|1W|B|J]|$9|1X|A|1Y|B|C]|$9|1Z|A|20|B|C]]|D|@]|E|$]]|$1|T|3|U|5|6|7|21|8|@$9|22|A|23|B|C]|$9|24|A|25|B|C]|$9|26|A|27|B|J]]|D|@]|E|$]]|$1|V|3|-4|5|6|7|28|8|@]|D|@]|E|$]]|$1|W|3|X|5|6|7|29|8|@]|D|@]|E|$]]|$1|Y|3|Z|5|10|7|2A|8|@]|D|@]|E|$11|12]]|$1|13|3|-4|5|6|7|2B|8|@]|D|@]|E|$]]]|14|$]]

As part of the C++ standard there exists some pre-defined macros that you can use. Section 16.8 of the C++ standard defines amongst other things, the <code>__LINE__</code> macro.

<blockquote>
 <code>__LINE__</code>: The line number of the current source line (a decimal
 constant). 
 <code>__FILE__</code>: The presumed name of the source file (a character string
 literal). 
 <code>__DATE__</code>: The date of translation of the source file (a character string
 literal...) 
 <code>__TIME__</code>: The time of translation of the source file (a character string
 literal...) 
 <code>__STDC__</code>: Whether<code>__STDC__</code> is predefined 
 <code>__cplusplus</code>: The name <code>__cplusplus</code> is defined to the value 199711L when
 compiling a C ++ translation unit
</blockquote>

So your code would be:

<pre><code>if(!Logical)
 printf("Not logical value at line number %d \n",__LINE__);
</code></pre>

blocks|key|308430|text|使用__LINE__+(即双下划线行双下划线)，预处理器将用遇到它的行号替换它。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|308431|entityMap^0|2|8|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|$]]

Use <code>__LINE__</code> (that's double-underscore LINE double-underscore), the preprocessor will replace it with the line number on which it is encountered.

blocks|key|310461|text|您应该使用预处理器宏__LINE__和__FILE__。它们是预定义的宏，是C/C%2B%2B标准的一部分。在预处理过程中，它们将分别替换为包含表示当前行号的整数的常量字符串和当前文件名。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|310462|其他预处理器变量：|310463|310464|__func__：函数名(这是it)|unordered-list-item|310465|__DATE__的一部分，并不是所有的C99编译器都支持it)|310466|__DATE__："Mmm+yyyy"|310467|__TIME__“形式的字符串："hh:mm:ss"|310468|形式的字符串|310469|310470|您的代码将是：|310471|if(!Logical)
++printf("Not+logical+value+at+line+number+%25d+in+file+%25s\n",+__LINE__,+__FILE__);|code-block|syntax|javascript|310472|entityMap|0|LINK|mutability|MUTABLE|url|http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2004/n1642.html^0|A|8|J|8|0|0|0|0|8|0|0|8|J|3|0|0|0|8|0|0|8|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|19|8|@$9|1A|A|1B|B|C]|$9|1C|A|1D|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|1E|8|@]|D|@]|E|$]]|$1|H|3|-4|5|6|7|1F|8|@]|D|@]|E|$]]|$1|I|3|J|5|K|7|1G|8|@$9|1H|A|1I|B|C]]|D|@]|E|$]]|$1|L|3|M|5|K|7|1J|8|@$9|1K|A|1L|B|C]]|D|@$9|1M|A|1N|1|1O]]|E|$]]|$1|N|3|O|5|K|7|1P|8|@$9|1Q|A|1R|B|C]]|D|@]|E|$]]|$1|P|3|Q|5|K|7|1S|8|@$9|1T|A|1U|B|C]]|D|@]|E|$]]|$1|R|3|S|5|6|7|1V|8|@]|D|@]|E|$]]|$1|T|3|-4|5|6|7|1W|8|@]|D|@]|E|$]]|$1|U|3|V|5|6|7|1X|8|@]|D|@]|E|$]]|$1|W|3|X|5|Y|7|1Y|8|@]|D|@]|E|$Z|10]]|$1|11|3|-4|5|6|7|1Z|8|@]|D|@]|E|$]]]|12|$13|$5|14|15|16|E|$17|18]]]]

You should use the preprocessor macro <code>__LINE__</code> and <code>__FILE__</code>. They are predefined macros and part of the C/C++ standard. During preprocessing, they are replaced respectively by a constant string holding an integer representing the current line number and by the current file name.

Others preprocessor variables :

<ul>
<li><code>__func__</code> : function name (this is part of <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2004/n1642.html" rel="noreferrer">C99</a>, not all C++ compilers support it)</li>
<li><code>__DATE__</code> : a string of form "Mmm dd yyyy"</li>
<li><code>__TIME__</code> : a string of form "hh:mm:ss"</li>
</ul>

<hr>

Your code will be :

<pre><code>if(!Logical)
 printf("Not logical value at line number %d in file %s\n", __LINE__, __FILE__);
</code></pre>

blocks|key|3043877|text|签出__FILE__和__LINE__宏|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3043878|entityMap^0|2|8|B|8|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|M|8|@]|D|@]|E|$]]]|G|$]]

Checkout <code>__FILE__</code> and <code>__LINE__</code> macros

blocks|key|305487|text|试试__FILE__和__LINE__。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|305488|您可能还会发现__DATE__和__TIME__很有用。|305489|但是，除非您必须在客户端调试程序，因此需要记录这些信息，否则您应该使用常规调试。|305490|entityMap^0|2|8|B|8|0|7|8|G|8|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@$9|M|A|N|B|C]|$9|O|A|P|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|Q|8|@$9|R|A|S|B|C]|$9|T|A|U|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|V|8|@]|D|@]|E|$]]|$1|J|3|-4|5|6|7|W|8|@]|D|@]|E|$]]]|K|$]]

Try <code>__FILE__</code> and <code>__LINE__</code>. 
You might also find <code>__DATE__</code> and <code>__TIME__</code> useful. 
Though unless you have to debug a program on the clientside and thus need to log these informations you should use normal debugging.

blocks|key|3043926|text|您可以使用与printf()具有相同行为的宏，只是它还包含调试信息，如函数名、类和行号：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3043927|#include+<cstdio>++//needed+for+printf
#define+print(a,+args...)+printf("%25s(%25s:%25d)+"+a,++__func__,__FILE__,+__LINE__,+##args)
#define+println(a,+args...)+print(a+"\n",+##args)|code-block|syntax|javascript|3043928|这些宏的行为应该与printf()相同，同时包含类似java+stacktrace的信息。下面是一个main示例：|3043929|void+exampleMethod()+{
++++println("printf()+syntax:+string+=+%25s,+int+=+%25d",+"foobar",+42);
}

int+main(int+argc,+char**+argv)+{
++++print("Before+exampleMethod()...\n");
++++exampleMethod();
++++println("Success!");
}|3043930|这将导致以下输出：|3043931|3043932|+main(main.cpp:11)在exampleMethod()之前...|blockquote|3043933|3043934|exampleMethod(main.cpp:7)+printf()语法:+string+=+foobar，int+=+42|3043935|main(main.cpp:13)成功！|3043936|entityMap^0|0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|X|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|Y|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Z|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|10|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|11|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|12|8|@]|9|@]|A|$]]|$1|N|3|O|5|P|7|13|8|@]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|14|8|@]|9|@]|A|$]]|$1|R|3|S|5|6|7|15|8|@]|9|@]|A|$]]|$1|T|3|U|5|6|7|16|8|@]|9|@]|A|$]]|$1|V|3|-4|5|6|7|17|8|@]|9|@]|A|$]]]|W|$]]

You could use a macro with the same behavior as printf(), 
except that it also includes debug information such as 
function name, class, and line number:

<pre><code>#include &lt;cstdio&gt; //needed for printf
#define print(a, args...) printf("%s(%s:%d) " a, __func__,__FILE__, __LINE__, ##args)
#define println(a, args...) print(a "\n", ##args)
</code></pre>

These macros should behave identically to printf(), while including java stacktrace-like information. Here's an example main:

<pre><code>void exampleMethod() {
 println("printf() syntax: string = %s, int = %d", "foobar", 42);
}

int main(int argc, char** argv) {
 print("Before exampleMethod()...\n");
 exampleMethod();
 println("Success!");
}
</code></pre>

Which results in the following output:

<blockquote>
 main(main.cpp:11) Before exampleMethod()... 
 exampleMethod(main.cpp:7) printf() syntax: string = foobar, int = 42 
 main(main.cpp:13) Success! 
</blockquote>

blocks|key|3043974|text|因为我现在也面临着这个问题，并且我不能添加一个不同但也是有效的here问题的答案，所以我将为这个问题提供一个示例解决方案:使用模板仅获取在C%2B%2B中调用函数的行号。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|3043975|背景:在C%2B%2B中，可以使用非类型整数值作为模板参数。这与将数据类型用作模板参数的典型用法不同。因此，我们的想法是在函数调用中使用这样的整数值。|3043976|#include+<iostream>

class+Test{
++++public:
++++++++template<unsigned+int+L>
++++++++int+test(){
++++++++++++std::cout+<<+"the+function+has+been+called+at+line+number:+"+<<+L+<<+std::endl;
++++++++++++return+0;
++++++++}
++++++++int+test(){+return+this->test<0>();+}
};

int+main(int+argc,+char+**argv){
++++Test+t;
++++t.test();
++++t.test<__LINE__>();
++++return+0;
}|code-block|syntax|javascript|3043977|输出：|3043978|3043979|已在第0行调用该函数|blockquote|3043980|3043981|已在第16行调用该函数|3043982|3043983|这里要提到的一件事是，在C%2B%2B11标准中，可以使用模板为函数提供默认模板值。在pre+C%2B%2B11中，非类型参数的默认值似乎只对类模板参数有效。因此，在C%2B%2B11中，不需要像上面那样有重复的函数定义。在C%2B%2B11中，使用const+char*模板参数也是有效的，但不能将它们与__FILE__或__func__这样的文字一起使用，就像前面提到的here。|style|CODE|3043984|因此，最后，如果您使用C%2B%2B或C%2B%2B11，这可能是一个非常有趣的替代方法，而不是使用宏来获取调用线路。|3043985|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/21022436/how-to-get-the-file-name-and-a-line-number-of-a-function-call|1|https://stackoverflow.com/questions/3773378/passing-const-char-as-template-argument^0|V|4|0|0|0|0|0|0|0|0|0|0|3T|8|42|8|4R|4|1|0|0^^$0|@$1|2|3|4|5|6|7|1A|8|@]|9|@$A|1B|B|1C|1|1D]]|C|$]]|$1|D|3|E|5|6|7|1E|8|@]|9|@]|C|$]]|$1|F|3|G|5|H|7|1F|8|@]|9|@]|C|$I|J]]|$1|K|3|L|5|6|7|1G|8|@]|9|@]|C|$]]|$1|M|3|-4|5|6|7|1H|8|@]|9|@]|C|$]]|$1|N|3|O|5|P|7|1I|8|@]|9|@]|C|$]]|$1|Q|3|-4|5|6|7|1J|8|@]|9|@]|C|$]]|$1|R|3|S|5|6|7|1K|8|@]|9|@]|C|$]]|$1|T|3|-4|5|6|7|1L|8|@]|9|@]|C|$]]|$1|U|3|V|5|6|7|1M|8|@$A|1N|B|1O|W|X]|$A|1P|B|1Q|W|X]]|9|@$A|1R|B|1S|1|1T]]|C|$]]|$1|Y|3|Z|5|6|7|1U|8|@]|9|@]|C|$]]|$1|10|3|-4|5|6|7|1V|8|@]|9|@]|C|$]]]|11|$12|$5|13|14|15|C|$16|17]]|18|$5|13|14|15|C|$16|19]]]]

Since i'm also facing this problem now and i cannot add an answer to a different but also valid question asked <a href="https://stackoverflow.com/questions/21022436/how-to-get-the-file-name-and-a-line-number-of-a-function-call">here</a>,
i'll provide an example solution for the problem of:
getting only the line number of where the function has been called in C++ using templates.
Background: in C++ one can use non-type integer values as a template argument. This is different than the typical usage of data types as template arguments.
So the idea is to use such integer values for a function call.
<pre><code>#include &lt;iostream&gt;

class Test{
 public:
 template&lt;unsigned int L&gt;
 int test(){
 std::cout &lt;&lt; &quot;the function has been called at line number: &quot; &lt;&lt; L &lt;&lt; std::endl;
 return 0;
 }
 int test(){ return this-&gt;test&lt;0&gt;(); }
};

int main(int argc, char **argv){
 Test t;
 t.test();
 t.test&lt;__LINE__&gt;();
 return 0;
}
</code></pre>
Output:
<blockquote>
the function has been called at line number: 0
the function has been called at line number: 16
</blockquote>
One thing to mention here is that in C++11 Standard it's possible to give default template values for functions using template. In pre C++11 default values for non-type arguments seem to only work for class template arguments. Thus, in C++11, there would be no need to have duplicate function definitions as above. In C++11 its also valid to have const char* template arguments but its not possible to use them with literals like <code>__FILE__</code> or <code>__func__</code> as mentioned <a href="https://stackoverflow.com/questions/3773378/passing-const-char-as-template-argument">here</a>.
So in the end if you're using C++ or C++11 this might be a very interesting alternative than using macro's to get the calling line.

blocks|key|3044007|text|通过使用std::source_location，C%2B%2B20提供了一种新的方法来实现这一点。目前，这是可以通过std::experimental::source_location和#include+<experimental/source_location>在gcc中访问的。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3044008|像__LINE__这样的宏的问题在于，如果您想创建一个输出当前行号和一条消息的日志记录函数，则必须始终将__LINE__作为函数参数传递，因为它在调用点处已展开。如下所示：|3044009|void+log(const+std::string+msg)+{
++++std::cout+<<+__LINE__+<<+"+"+<<+msg+<<+std::endl;
}|code-block|syntax|javascript|3044010|将始终输出函数声明的行，而不是实际调用log的行。另一方面，使用std::source_location你可以写下这样的代码：|3044011|#include+<experimental/source_location>
using+std::experimental::source_location;

void+log(const+std::string+msg,+const+source_location+loc+=+source_location::current())
{
++++std::cout+<<+loc.line()+<<+"+"+<<+msg+<<+std::endl;
}|3044012|在这里，使用指向调用log的位置的行号初始化loc。You+can+try+it+online+here.|3044013|entityMap|0|LINK|mutability|MUTABLE|url|https://en.cppreference.com/w/cpp/utility/source_location|1|https://godbolt.org/z/mtS6hz^0|1J|Y|2I|13|4|K|0|0|1|8|1G|8|0|0|J|3|W|K|0|0|A|3|M|3|Q|R|1|0^^$0|@$1|2|3|4|5|6|7|12|8|@$9|13|A|14|B|C]|$9|15|A|16|B|C]]|D|@$9|17|A|18|1|19]]|E|$]]|$1|F|3|G|5|6|7|1A|8|@$9|1B|A|1C|B|C]|$9|1D|A|1E|B|C]]|D|@]|E|$]]|$1|H|3|I|5|J|7|1F|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|1G|8|@$9|1H|A|1I|B|C]|$9|1J|A|1K|B|C]]|D|@]|E|$]]|$1|O|3|P|5|J|7|1L|8|@]|D|@]|E|$K|L]]|$1|Q|3|R|5|6|7|1M|8|@$9|1N|A|1O|B|C]|$9|1P|A|1Q|B|C]]|D|@$9|1R|A|1S|1|1T]]|E|$]]|$1|S|3|-4|5|6|7|1U|8|@]|D|@]|E|$]]]|T|$U|$5|V|W|X|E|$Y|Z]]|10|$5|V|W|X|E|$Y|11]]]]

C++20 offers a new way to achieve this by using <a href="https://en.cppreference.com/w/cpp/utility/source_location" rel="noreferrer">std::source_location</a>. This is currently accessible in gcc an clang as <code>std::experimental::source_location</code> with <code>#include &lt;experimental/source_location&gt;</code>.

The problem with macros like <code>__LINE__</code> is that if you want to create for example a logging function that outputs the current line number along with a message, you always have to pass <code>__LINE__</code> as a function argument, because it is expanded at the call site.
Something like this:

<pre class="lang-cpp prettyprint-override"><code>void log(const std::string msg) {
 std::cout &lt;&lt; __LINE__ &lt;&lt; " " &lt;&lt; msg &lt;&lt; std::endl;
}
</code></pre>

Will always output the line of the function declaration and not the line where <code>log</code> was actually called from.
On the other hand, with <code>std::source_location</code> you can write something like this:

<pre class="lang-cpp prettyprint-override"><code>#include &lt;experimental/source_location&gt;
using std::experimental::source_location;

void log(const std::string msg, const source_location loc = source_location::current())
{
 std::cout &lt;&lt; loc.line() &lt;&lt; " " &lt;&lt; msg &lt;&lt; std::endl;
}
</code></pre>

Here, <code>loc</code> is initialized with the line number pointing to the location where <code>log</code> was called.
<a href="https://godbolt.org/z/mtS6hz" rel="noreferrer">You can try it online here.</a>

blocks|key|308540|text|对于那些可能需要它的人，一个"FILE_LINE“宏可以方便地打印文件和行：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|308541|#define+STRINGIZING(x)+#x
#define+STR(x)+STRINGIZING(x)
#define+FILE_LINE+__FILE__+":"+STR(__LINE__)|code-block|syntax|javascript|308542|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|$]]

For those who might need it, a "FILE_LINE" macro to easily print file and line:

<pre><code>#define STRINGIZING(x) #x
#define STR(x) STRINGIZING(x)
#define FILE_LINE __FILE__ ":" STR(__LINE__)
</code></pre>

In the sake of debugging purposes, can I get the line number in C/C++ compilers?
(standard way or specific ways for certain compilers)

e.g

<pre><code>if(!Logical)
 printf("Not logical value at line number %d \n",LineNumber);
 // How to get LineNumber without writing it by my hand?(dynamic compilation)
</code></pre>

C/C++ line number

编译器

出于调试目的，我可以在C/C++编译器中获取行号吗？(某些编译器的标准方式或特定方式)e.gif(!Logical)    printf("Not logical value at line number %d \n",LineNumber);    // How to get LineNumber without w...

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