C++ 用枚举类型替代宏定义连续的常量

用define定义16种颜色常量要写16行代码，改成枚举类型后只要一两行就搞定：

#define    cBlack     0
#define    cNavy      1
#define    cGreen    2
#define    cTeal       3
#define    cMaroon  4
#define    cPurple    5
#define    cOlive      6
#define    cSliver     7
#define    cGray      8
#define    cBlue       9
#define    cLime      10
#define    cCyan      11
#define    cRed        12
#define    cMagenta 13
#define    cYellow     14
#define    cWhite      15

enum cColor{ cBlack=0,cNavy,cGreen,cTeal,cMaroon,cPurple, cOlive, cSliver,
			 cGray,   cBlue,cLime, cCyan,cRed,   cMagenta,cYellow,cWhite };

 之前写的《重载操作符＜＜实现cout定位输出以及设置颜色》，其代码就可以改进为：

#include <iostream>
#include <windows.h>
using namespace std;

struct HannsC { DWORD fc; DWORD bg; };
struct HannXy { SHORT pX; SHORT pY; };

enum cColor{ cBlack=0,cNavy,cGreen,cTeal,cMaroon,cPurple, cOlive, cSliver,
			 cGray,   cBlue,cLime, cCyan,cRed,   cMagenta,cYellow,cWhite };

HannsC setC(DWORD fc = 7, DWORD bg = 0)
{
	fc %= 16, bg %= 16;
	HANDLE hConsole = GetStdHandle(STD_OUTPUT_HANDLE);
	SetConsoleTextAttribute(hConsole,fc|bg<<4);
	return {fc, bg*16};
}

HannXy Goto(SHORT x = 0, SHORT y = -1)
{
    CONSOLE_SCREEN_BUFFER_INFO pBuffer;
	COORD position = {x, y};
    HANDLE hConsole = GetStdHandle(STD_OUTPUT_HANDLE); 
	if (position.Y==-1){
		GetConsoleScreenBufferInfo(hConsole, &pBuffer); 
		position.Y = pBuffer.dwCursorPosition.Y;
	}    
    SetConsoleCursorPosition(hConsole, position);
	return {x, y};
}

ostream& operator<<(ostream& _os, HannsC _mc) {	return _os;}
ostream& operator<<(ostream& _os, HannXy _xy) {	return _os;}
ostream& cr(ostream& _os) {	_os.put('\n');_os.flush();return _os;}
 
int main(void)
{
	cout << setC(cNavy,cLime) << "abcdefghijklmnopqrstuvwxyz" << cr;
	cout << Goto(16,3) << setC(cYellow,cBlue) << "abcdefghijkl" 
		 << setC(cBlue,cYellow) << Goto(30) << 123 << cr << cr;
	cout << setC(cMagenta,cOlive) << 12312303236131230 << cr;
	cout << setC(cGreen,cWhite) << Goto(18,9) << "3.1415926535897932384626";
	cout << Goto(30) << setC(cRed) << "END!" << Goto() << "cr && !lf";
	
	cout << setC(cCyan) << cr << cr << "my C++ version: " << __cplusplus ;
	cout << setC() << cr;

	return 0;
}

同时，也把原来放在 operator<<() 中的实现功能部分，移到setC()和Goto()函数中，这样更好理解可读性更好。