C / C++ / MFC

CodingLover wrote:

If I use str as a standard string in c++, how can I do this format.

std::stringstream strstream;<br />
strstream << "Some data: " << 123;<br />
strstream.str(); // will give you a std::string object.

CodingLover wrote:

CString str = "Some Data";
str.Format(_T("%s%d"), str, 123) );

Nibu babu thomas wrote:

Doesn't this crash? You are passing str to str.Format function!!

I appreciate your help all the time...
CodingLover

CodingLover wrote:

Actually I dot this from MSDN and it gives only a compile error that, addition ) at the end.

The call will fail if the string object itself is offered as a 
parameter to Format. For example, the following code:

CString str = "Some Data";
str.Format("%s%d", str, 123);   // <code>Attention: str is also used in the parameter list.</code>

will cause unpredictable results.

MSDN:
When you pass a character string as an optional argument, you must
cast it explicitly as LPCTSTR. 

bob16972 wrote:

Your advice to avoid it is good. However, alot of people will get enough positive behavior that they will convince themselves you are crying the "sky is falling".

CodingLover wrote:

Ok, in such a case what should I do?

CString str;
str.Format("%s%d", _T( "Some Data" ), 123);

TCHAR strBuffer[ 255 ]; // you can tweak this down to what ever size you need, or use a pointer
_stprintf( strBuffer, _T("%s%d"), _T("Some Data: "), 123 );
// or you can be safe and use
_sntprintf( strBuffer, 255, _T("%s%d"), _T("Some Data: "), 123 );

// VanillaConsole.cpp : Defines the entry point for the console application.
//
 
#include "stdafx.h"
#include <string>
#include <iostream>
#include <sstream>
using namespace std;
 
int main()
{
	ostringstream oss;
	oss << "Some data" << 123;
	string s = oss.str();
 
	cout << s << endl;
 
	return 0;
}

// VanillaConsole.cpp : Defines the entry point for the console application.
//
 
#include "stdafx.h"
#include <iostream>
#include <boost/format.hpp>
using namespace std;
using namespace boost;
 
int main()
{
	cout << format("%1% %2%") % "Some Data" % 123 << endl;
 
	return 0;
}