string封装一些小函数

1、去掉字符串开头和结尾的空格

string trimWhiteSpaces(string strIn)    {        string strOut = strIn;        if (!strOut.empty())        {            while (strOut.size() > 0)            {                if (strOut[0] == ' ')                {                    strOut = strOut.substr(1, strOut.size() -1);                }                else                {                    break;                }            }            while (strOut.size() > 0)            {                if (strOut[strOut.size() - 1] == ' ')                {                    strOut = strOut.substr(0, strOut.size() -1);                }                else                {                    break;                }            }        }        return strOut;    }