预处理器

来自cppreference.com
< cpp

This page has been machine-translated from the English version of the wiki using Google Translate.

The translation may contain errors and awkward wording. Hover over text to see the original version. You can help to fix errors and improve the translation. For instructions click here.

Click here for the English version of this page

 
C++
 
C + +语言
大会的主题
Original:
General topics
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
预处理器
评论
关键字
流量控制
Original:
Flow control
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
条件执行语句
Original:
Conditional execution statements
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
迭代语句
Original:
Iteration statements
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
跳转语句
Original:
Jump statements
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
功能
Original:
Functions
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
函数声明
lambda函数的声明
函数模板
的历史。内嵌说明
异常规范 （过时了）
noexcept说明 （C++11）
例外
Original:
Exceptions
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
命名空间
Original:
Namespaces
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
类型
Original:
Types
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
decltype specifier （C++11）
规范
Original:
Specifiers
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
CV符
存储时间说明符
constexpr说明 （C++11）
汽车符 （C++11）
alignas说明 （C++11）
初始化
Original:
Initialization
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
常
Original:
Literals
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
布尔文字
nullptr （C++11）
用户定义的 （C++11）
表达式
Original:
Expressions
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
另一种表示形式
实用工具
Original:
Utilities
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
类型
Original:
Types
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
typedef declaration
声明类型别名 （C++11）
属性 （C++11）
施放
Original:
Casts
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
隐式转换
const_cast conversion
static_cast conversion
dynamic_cast conversion
reinterpret_cast conversion
C-风格和功能转换
内存分配
Original:
Memory allocation
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
类
Original:
Classes
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
类特定的功能特性
Original:
Class-specific function properties
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
虚函数
覆盖说明 （C++11）
最后说明 （C++11）
明确的 （C++11）
静态的
特殊的成员函数
Original:
Special member functions
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
模板
Original:
Templates
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
类模板
函数模板
模板特化
参数包 （C++11）
杂项
Original:
Miscellaneous
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
内联汇编
 
预处理器
 

预处理器在编译开始之前运行。预处理的结果是单个的文件，它之后会传递给实际的编译器。

[编辑] 指令

预处理指令控制着预处理器的行为。每个指令占用一行，并具有以下的格式：

  • #字符
  • 预处理指令（define、undef、include、if、ifdef、ifndef、else、elif、endif、line、error、warning、pragma 之一）
  • 参数（取决于指令）
  • 换行符

空指令（#后跟一个换行符）是允许的，它没有效果。

[编辑] 功能

预编译器有翻译源文件的功能：

  • 有条件地编译源文件的若干部分（由指令 #if、#ifdef、#ifndef、#else、#elif 和 #endif 控制）。
  • 替换文本宏，而可能是串联或引用标识符（由指令#define和#undef，符号#和##控制）
    Original:
    replace text macros while possibly concatenating or quoting identifiers (controlled by directives #define and #undef, and operators # and ##)
    The text has been machine-translated via Google Translate.
    You can help to correct and verify the translation. Click here for instructions.
  • 包含其他文件（由指令#include控制）
  • 产生一个警告（由指令#warning控制）
  • 产生一个错误（由指令#error控制）
的预处理器可以控制以下几个方面：
Original:
The following aspects of the preprocessor can be controlled:
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
来自“http://zh.cppreference.com/mwiki/index.php?title=cpp/preprocessor&oldid=29267”