void Trim(string& inout_s)
{
// Remove leading and trailing whitespace
static const char whitespace[] = " \n\t\v\r\f";
inout_s.erase(0, inout_s.find_first_not_of(whitespace));
inout_s.erase(inout_s.find_last_not_of(whitespace) + 1U);
}
inout_s.erase(0, inout_s.find_first_not_of(whitespace));将字符串前面的空白区域去掉
inout_s.erase(inout_s.find_last_not_of(whitespace) + 1U);将字符串后面的空白区域去掉