C++实现urlencode,urldecode

namespace HttpUtility
{typedef unsigned char BYTE;inline BYTE toHex(const BYTE &x){return x > 9 ? x -10 + 'A': x + '0';}inline BYTE fromHex(const BYTE &x){return isdigit(x) ? x-'0' : x-'A'+10;}inline string URLEncode(const string &sIn){string sOut;for( size_t ix = 0; ix < sIn.size(); ix++ ){      BYTE buf[4];memset( buf, 0, 4 );if( isalnum( (BYTE)sIn[ix] ) ){      buf[0] = sIn[ix];}//else if ( isspace( (BYTE)sIn[ix] ) ) //貌似把空格编码成%20或者+都可以//{//    buf[0] = '+';//}else{buf[0] = '%';buf[1] = toHex( (BYTE)sIn[ix] >> 4 );buf[2] = toHex( (BYTE)sIn[ix] % 16);}sOut += (char *)buf;}return sOut;};inline string URLDecode(const string &sIn){string sOut;for( size_t ix = 0; ix < sIn.size(); ix++ ){BYTE ch = 0;if(sIn[ix]=='%'){ch = (fromHex(sIn[ix+1])<<4);ch |= fromHex(sIn[ix+2]);ix += 2;}else if(sIn[ix] == '+'){ch = ' ';}else{ch = sIn[ix];}sOut += (char)ch;}return sOut;}
}