C++将username部分用*取代

#include<string.h>
#include<stdlib.h>
#define toStar(str,start,end) \
	do{ \
	for(int i=start;i<end;i++)\
		{ \
		str[i] = '*';\
		} \
	}while(0)
//GBK
const char* toStarString(const char* username)
{
	int len = strlen(username);
	char *starName = new char[len+1];
	strcpy(starName,username);
	int start = 1;       //默认保留头尾字符
	int end = len - 1;

	unsigned char ch = starName[0];                 //取头字符
	//if(isalnum(ch)) {toStar(starName,3,len-3);}
	if ( ch >= 0xB0 && ch <= 0xF7 )             //推断头是否为汉字
	{
		//继续检查下一个字符能否组织成汉字
		unsigned char ch1=starName[1];
		if ( ch1 >=0xA1 && ch1 <= 0xFE )
		{
			start = 2;
		}
	}
	ch = starName[len-1];           //尾字符
	if(ch >=0xA1 && ch <= 0xFE)
	{
		unsigned char ch1=starName[len-2];
		if ( ch1 >= 0xB0 && ch1 <= 0xF7 )
		{
			end = len - 2;
		}
	}

	if(start<=end-1) toStar(starName,start,end);
	else toStar(starName,end,len);
	return starName;
}
//Unicode
const wchar_t* toStarUn(const wchar_t* username)
{
	int len = wcslen(username);
	wchar_t *starName = new wchar_t[len+1];
	wcscpy(starName,username);
	if(len>2) toStar(starName,1,len-1);
	else if(len == 2) toStar(starName,1,len);
	return starName;
}