C / C++ / MFC

<br />
bool ReadPort()<br />
{<br />
     long int dwSize = 0;<br />
     bool hResult = false;<br />
     std::string sb = "";<br />
     DWORD dwEventMask;<br />
<br />
     if(!SetCommMask(hComm, EV_RXCHAR)) /* Setting Event Type */<br />
	 {	<br />
        return hResult;<br />
     }<br />
<br />
	if(WaitCommEvent(hComm, &dwEventMask, NULL)) /* Waiting For Event to Occur */<br />
	{<br />
		char szBuf[1024];<br />
		DWORD dwIncommingReadSize;<br />
<br />
		do<br />
		{<br />
			if(ReadFile(hComm, &szBuf, 1024, &dwIncommingReadSize, NULL) != 0)<br />
			{<br />
				if(dwIncommingReadSize > 0)<br />
				{<br />
					dwSize += dwIncommingReadSize;<br />
				    sb.append(szBuf);<br />
				}<br />
				hResult = true;<br />
			}<br />
<br />
			else<br />
			{<br />
				unsigned long error = ::GetLastError();<br />
				hResult = false;<br />
				printf("the error while reading error is %dl\n", error);<br />
				break;<br />
			}<br />
		} while(dwIncommingReadSize > 0);<br />
<br />
		*readData = new char[dwSize];<br />
		strcpy(*readData, sb.c_str());<br />
		return hResult;<br />
	}<br />
    else<br />
    {<br />
		return hResult;<br />
    }<br />
<br />
}<br />

George_George wrote:

For trim, I use find first/last not of space technique, and for toupper/tolower, I always change them manually by adding some value to 'a' to form 'A' or vice versa.

My question is I want to find some best practices to implement them (one reason is I think my private implementation may be error prone and the other reason is I am not sure whether there is existing APIs which could be utilized) and comment about my current implementation issues.

std::string Str = "nibu babu thomas";
std::transform( Str.begin(), Str.end(), Str.begin(), toupper );
std::cout << Str;

George_George wrote:

How about trim? No built-in APIs?

void Trim( const std::string& StrToTrim, std::string& TrimmedString )
{
   std::string::size_type First = StrToTrim.find_first_not_of( ' ' ); // Find first non space char
   std::string::size_type Last = StrToTrim.find_last_not_of( ' ' ) + 1; // First first last non space char
   TrimmedString = StrToTrim.substr( First, Last - First ); // Return substring
}

int main()
{
   std::string StrToTrim = "   32  Nibu babu thomas   2342 2 23 3    ";
   std::string TrimmedString = "On return will hold trimmed string";
   Trim( StrToTrim, TrimmedString );
   
   return 0;
}

George_George wrote:

Do you have any reference documents?

George_George wrote:

1.

No document which describes all possible exceptions may be thrown by a specific STL function, like string.substr?

2.

"the files exception and stdexcept" -- yes, but for a specific STL function like string.substr, how do you check all possible exceptions may be thrown by looking at the file? Smile

void Trim( const std::string& StrToTrim, std::string& TrimmedString )
{
   // Find first non whitespace char in StrToTrim
   std::string::size_type First = StrToTrim.find_first_not_of( ' ' );
   // Check whether something went wrong?
   if( First == std::string::npos )
   {
      First = 0;
   }

   // Find last non whitespace char from StrToTrim
   std::string::size_type Last = StrToTrim.find_last_not_of( ' ' );
   // If something didn't go wrong, Last will be recomputed to get real length of substring
   if( Last != std::string::npos )
   {
      Last = ( Last + 1 ) - First;
   }

   // Copy such a string to TrimmedString
   TrimmedString = StrToTrim.substr( First, Last );
}

Christian Flutcher wrote:

1 - Person anotherPerson is declared but not initialized. But still calls to anotherPerson.GetName() worked. How this is happening?

Christian Flutcher wrote:

2 - Is there any difference when allocating memory for *person and anotherPerson?

Christian Flutcher wrote:

3 - I know we should delete the pointer variables to claim memory. But AFAIK, there is no need to delete the anotherPerson variable. How it gets removed from memory?

Somethings seem HARD to do, until we know how to do them.
_AnShUmAn_

_AnShUmAn_ wrote:

Yes. The memory is allocated from heap in case you use new (ie *person), otherwise it is allocated from stack.

Cedric Moonen wrote:

Allocating/deallocating a lot of variables on the heap can lead to memory fragmentation which can be an issue if you tend to do it a lot