#define inpw(port) (*((volatile word *) (port))) #define inpdw(port) (*((volatile dword *)(port))) #define outp(port, val) (*((volatile byte *) (port)) = ((byte) (val))) #define outpw(port, val) (*((volatile wor
#define area(x) (x)*(x),对于area(2+2),替换为(2+2)*(2+2)=16,可以解决,但是对于area(2+2)/area(2+2)又会怎么样呢,有的学生一看到这道题马上给出结果,因为分子分母一样,又错了,还是忘了遵循先替换再计算的规则了,这道题替换后会变为(2+2)*(2+2)/(2+2)*(2+2)即4*4/4*4按照乘除...
In C programming, header files serve as a way to declare function prototypes, types, and macros that can be shared across multiple source files. The syntax of header files typically consists of the following elements: #ifndef HEADER_NAME_H#define HEADER_NAME_H // Declarations and definitions ...
Library interface(库接口), header file（头文件） "flib.h":// flib.h#ifndef FLIB_H#define FLIB_Hvoidf(void); // function declaration with external linkageexternint state; // variable declaration with external linkage#endif// FLIB_H Application code（应用代码）, source file（源文件） "...
#if, #elif利用后方的常数表达式(constant-expression)来判断程式码区段是否需要被包含 例如下面简单的程式码片段,因为test被定义成1,这个条件恰好吻合第一个区段,所以会编译并执行#if到#else之间区段 #include <stdio.h> #define test 1 int main(){ #if (test == 1) printf("Macro test exist...");...
众所又周知,`constexpr'关键字是在C++11时加入C++的,但在这之前,并不代表C++就没有“编译期常量”,除了大家都熟悉的#define和enum之外,以下写法也是可以的:然而我们会发现,以上代码如果用C编译器编的话,就又编不过了。报错会分两种:1. 编译器不支持或者禁用了VLA:会提示“nitems”并不是一个constant ...
int scores[NUM_TURNS]; // use of constant ...};还有一点，正如你看到的，上面的语句是NUM_TURNS的声明，而不是定义，所以你还必须在类的实现代码文件中定义类的静态成员：const int GamePlayer::NUM_TURNS; // mandatory definition;// goes in class impl.file 你不必过于担心这种小事。如果...
#define _x "there" char* func() { return "hello"_x; } int main() { char * p = func(); return 0; } 該編譯器會將此程式碼解譯為後面接著巨集的字串常值 "hello",且將該巨集展開成 "there",然後將這兩個字串常值串連成一個。 在 Visual Studio 2015 中,編譯器會將此序列解譯為使用...
Example:coder.cinclude('<sysheader.h>') For a header file that is not a system header file, omit the angle brackets. The generated#includestatement for a header file that is not a system header file has the format#include "myHeader". The header file must be in the current folder or ...
If the source code is not available, the function declaration in the header file is displayed. To change source files and their dependencies, or to define and select function array layouts, click the custom code settings button to open the Simulation Target pane in Model Configuration Parameters....