dev-cpp-users Mailing List for Dev-C++

  -----Original Message-----
  From: dev...@li...
[mailto:dev...@li...]On Behalf Of Nathan
Binette
  Sent: Saturday, November 30, 2002 3:11 PM
  To: dev...@li...
  Subject: [Dev-C++] type mismatch


  When writing a basic program to perform a calcuation I have set types as
float to receive input (cin).  When I enter a character (not a number) when
prompted for input the program terminates.  This happens even when using
exception handling

      cin.exceptions(cin.failbit);
      try{  }
      catch (...) {   };

  I've enabled exception handling via compiler options but this does not
help?  Can anyone offer any comments on how to avoid program termination
when type mismatch occurs?

  Thanks, Nate
  [[Ken]: ]

  Why not receive a string, check for validity, and convert to a float?

  atof() means ASCII to float
  atol() means ASCII to long
  atoi() means ASCII to int

  #include <stdlib.h>
  price = atof (mybuffer);

  Checkout http://www.cplusplus.com/doc/tutorial/tut3-2.html.
  Ken Bradford
  Alpha II Service, Inc.
  (614)868-5033

You can't use switch on a value which is not known at compile time.
instead, do a compare in default:
	default:
		if (message == WM_MYMESSAGE)
		{
			/* Do some stuff */		
		}
		else
		{
			return DefWindowProc (hwnd, message, wParam,
lParam);
		}

The other part of the story is that you shouldn't assign the value of a
variable in the header file, but do this in the implementation file.

> -----Original Message-----
> From: Marc Heiligers [mailto:ma...@e-...]
> Sent: Monday, December 02, 2002 02:32 PM
> To: dev-cpp-users-list
> Subject: [Dev-C++] Problem with RegisterWindowMessage()
> 
> 
> I have a little problem. I have a header file which I include 
> in my main
> file (surprise surprise). In the header I have the following:
> 
> const UINT WM_MYMESSAGE = RegisterWindowMessage(_T("some message"));
> 
> Right, now in my main WindowProc I have a switch statement like so:
> 
> LRESULT CALLBACK WindowProc(HWND hwnd, UINT message, WPARAM 
> wParam, LPARAM
> lParam)
> {
>     switch (message)                  /* handle the messages */
>     {
>       case WM_DESTROY:
>             PostQuitMessage (0);       /* send a WM_QUIT to 
> the message
> queue */
>             break;
> 	/* 
> 		And some more message handlers here
> 		more
> 		more
> 	*/
> 	case WM_MYMESSAGE:
> 		/*Do some stuff*/
> 	default:
> 		return DefWindowProc (hwnd, message, wParam, lParam);
>     }
>     return 0;
> }
> 
> So far so good. Now when I compile I get the following little message:
> 
> "case label `WM_MYMESSAGE' does not reduce to an integer constant"
> 
> Now, personally, I thought that a "const UINT" was an integer 
> constant, but
> clearly g++ disagrees. The funny thing is I have used similar 
> code with VC++
> v6 and not had the same problem. Any ideas of how I can 
> convince g++ that
> this is the case would be appreciated.
> 
> _____________________________
> Marc Heiligers
> 
> PS. I've had coffee before I wrote this, so I'm pretty sure 
> I'm thinking
> straight (for a change).
> 
> 
> -------------------------------------------------------
> This sf.net email is sponsored by:ThinkGeek
> Welcome to geek heaven.
> http://thinkgeek.com/sf
> _______________________________________________
> Dev-cpp-users mailing list
> Dev...@li...
> TO UNSUBSCRIBE: http://www.noicys.cjb.net/devcpp/ub.htm
> https://lists.sourceforge.net/lists/listinfo/dev-cpp-users
> 

I have a little problem. I have a header file which I include in my main
file (surprise surprise). In the header I have the following:

const UINT WM_MYMESSAGE = RegisterWindowMessage(_T("some message"));

Right, now in my main WindowProc I have a switch statement like so:

LRESULT CALLBACK WindowProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM
lParam)
{
    switch (message)                  /* handle the messages */
    {
      case WM_DESTROY:
            PostQuitMessage (0);       /* send a WM_QUIT to the message
queue */
            break;
	/* 
		And some more message handlers here
		more
		more
	*/
	case WM_MYMESSAGE:
		/*Do some stuff*/
	default:
		return DefWindowProc (hwnd, message, wParam, lParam);
    }
    return 0;
}

So far so good. Now when I compile I get the following little message:

"case label `WM_MYMESSAGE' does not reduce to an integer constant"

Now, personally, I thought that a "const UINT" was an integer constant, but
clearly g++ disagrees. The funny thing is I have used similar code with VC++
v6 and not had the same problem. Any ideas of how I can convince g++ that
this is the case would be appreciated.

_____________________________
Marc Heiligers

PS. I've had coffee before I wrote this, so I'm pretty sure I'm thinking
straight (for a change).

Heya.

Whenever trying to use the function getopts() in a program the linker
kindly says that it can't find any refrence to the options getopts (or
getops_long for that matter).. Anyone else seen this, or someone might
know a remedy?



Mvh/Best regards,

Arnvid L. Karstad