Filename and line information
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< cpp | preprocessor
 |
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包括其他源文件后，立即指令到当前源文件的行.
原文：
Includes other source file into current source file at the line immediately after the directive .
目录 |
[编辑] 语法
#line lineno
|
(1) | ||||||||
#line lineno "filename"
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(2) | ||||||||
[编辑] 解释
改变目前的预处理行号，lineno超越了这一点。展开的宏观__LINE__将扩大到lineno加上一些实际遇到的源代码行以来
2) 原文：
Changes the current preprocessor line number to lineno. Expansions of the macro __LINE__ beyond this point will expand to lineno plus the number of actual source code lines encountered since.
改变当前的预处理文件名filename的宏观扩张__FILE__从这个角度会产生filename
原文：
Also changes the current preprocessor file name to filename. Expansions of the macro __FILE__ from this point will produce filename.
任何预处理标记（宏常数或表达式）都可以作为参数
#line，只要他们扩大到一个有效的十进制整数，可以有效的字符串原文：
Any preprocessing tokens (macro constants or expressions) are permitted as arguments to
#line as long as they expand to a valid decimal integer optionally following a valid character string.[编辑] 注释
使用此指令在这种情况下，一些自动代码代工具它产生Ç+ +源文件从另一种语言编写的文件。
#line指令插入在的产生Ç+ +文件引用的行数和在文件名的原（人可编辑）源文件原文：
This directive is used by some automatic code generation tools which produce C++ source files from a file written in another language. In that case,
#line directives may be inserted in the generated C++ file referencing line numbers and the file name of the original (human-editable) source file.[编辑] 示例
#include <cassert> #define FNAME "test.cc" int main() { #line 777 FNAME assert(2+2 == 5); }
输出：
test: test.cc:777: int main(): Assertion `2+2 == 5' failed.
