C / C++ / MFC

Re: How to access program call arguments?

20-Dec-07 12:10

If the program is the sort with a visible `int main(argc,argv)' function, the answer is easy.

But what in the Windows type of program that is called through a WinMain()? In Borland C++ 4.5, there are two system-declared variables _Argc and _Argv which on entry to WinMain point to the program's call argument table; but that does not work in Visual C++ 2008.

Steve Echols20-Dec-07 12:22

Steve Echols

20-Dec-07 12:22

There's a Win32 function called GetCommandLine[^]

And CommandLineToArgv will split it into an array for you.

- S
50 cups of coffee and you know it's on!

Re: How to access program call arguments?

Anthony Appleyard20-Dec-07 20:31

Re: How to access program call arguments?

20-Dec-07 20:31

Thanks.

CPallini20-Dec-07 12:28

Re: Getting objects in ROT

20-Dec-07 12:28

Does documentation
http://msdn2.microsoft.com/en-us/library/ms633559.aspx[^]
help, doesn't it?
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

[my articles]

Getting objects in ROT

Akin Ocal20-Dec-07 12:07

Akin Ocal

20-Dec-07 12:07

http://www.alexfedotov.com/samples/enumrot.asp

I can enumerate objects in ROT using the code in the link.

How can I get objects exposed by these running objects ?

Will I use IMoniker::BindToObject for the rest ?

Regards...

Stephen Hewitt20-Dec-07 13:55

Stephen Hewitt

20-Dec-07 13:55

It would help if I knew what you're trying to achieve but yes, generally you'd call BindToObject. In other scenarios you'd call BindToStorage.

Steve

modified on Thursday, December 20, 2007 9:33:44 PM

ifstream slow to close

Budric B.20-Dec-07 11:05

Budric B.

20-Dec-07 11:05

Hi,
I'm getting some terrible performance when calling ifstream close. It takes about the same amount of time to close() as it takes to read my 64 Mb of data! I've been playing around with it and found it only happens if I have been writing to a file recently. Here's my test code:

void readTest(const std::string & path) 
{
	ifstream in;
	in.open(path.c_str(), ios_base::in | ios_base::binary);
	char * buffer = new char[67108864];
	in.read(buffer, 67108864);
	SW_ELAPSED_MSG()
	in.close();
	SW_ELAPSED_MSG()
	delete [] buffer;
}

void writeTest(const std::string & path)
{
	ofstream out;
	out.open(path.c_str(), ios_base::out | ios_base::binary);
	char * buffer = new char[67108864];
	out.write(buffer, 67108864);
	//out.flush();
	out.close();
	delete [] buffer;
}

int _tmain(int argc, _TCHAR* argv[])
{
	writeTest("testfile");
	SW_START();
	readTest("testfile");
	SW_ELAPSED_MSG()
        return 0;
}

Note my macros do the timing and display it on screen. I don't believe there's any problem with that code.
So anyone know why? I'm closing the streams. Why is the read stream affected at all by the write stream? Also as you can see I have a flush() statement in there. It doesn't help, commented or not.

Runtime error - incompatible iterator - why???

Philstix20-Dec-07 10:47

20-Dec-07 10:47

Hi,

I'm stumped.

Why does this code compile without problems but cause a runtime error? ("Debug Assertion Failed! ... Expression: vector iterators incompatible")

<br />
   vector< vector<string> >::iterator vvsi_b = (a.Block()).begin();<br />
   vector< vector<string> >::iterator vvsi_e = (a.Block()).end();<br />
<br />
   for (; vvsi_b != vvsi_e; ++vvsi_b)<br />
   {<br />
     // can be anything or nothing in the for loop - same result<br />
   }<br />
   </string></string>

a.Block() returns a const reference to a vector< vector< string > > object

I'm using Visual C++ 2005 Express.

Any help (and consequent hair retention) greatly appreciated.

Phil

Philstix20-Dec-07 10:50

20-Dec-07 10:50

Correction:

The quoted code should be:

vector< vector<string> >::iterator vvsi_b = (a.Block()).begin();
vector< vector<string> >::iterator vvsi_e = (a.Block()).end();

for (; vvsi_b != vvsi_e; ++vvsi_b)
{
// etc.
}

Phil

Philstix20-Dec-07 10:53

20-Dec-07 10:53

The codeproject message parser keeps removing part of the code I'm posting.

The code should refer to a vector of vector of string, but the string part keeps being removed from the post. How do I post so the code stays the way I want?

Phil

CPallini20-Dec-07 11:37

20-Dec-07 11:37

Member 73301 wrote:
The code should refer to a vector of vector of string, but the string part keeps being removed from the post. How do I post so the code stays the way I want?

post code snippets between <pre> TAGS, i.e.
<pre>
...code here..
...code here...
</pre>

also when showing templates use the escape sequence for < (<).

Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

[my articles]

Philstix20-Dec-07 15:34

20-Dec-07 15:34

Ok, the code that fails in Visual C++ 2005 Express is (if this formats ok):

vector < vector < string > > ::iterator vvsi_b = (a.Block()).begin();
vector < vector < string > > ::iterator vvsi_e = (a.Block()).end();
for (; vvsi_b != vvsi_e; ++vvsi_b)
{
// can be anything or nothing in the for loop - same result
}

Any idea why this causes the runtime error "Debug Assertion Failed! ... Expression: vector iterators incompatible" ?

Phil

Stephen Hewitt20-Dec-07 15:36

Stephen Hewitt

20-Dec-07 15:36

Where is the assertion happening? What line in your code?

Steve

Philstix20-Dec-07 17:28

Class/struct declarations and bit patterns

20-Dec-07 17:28

Thanks for replying.

The assertion isn't in my code as such it's in line 238 of the vector header file:

#if _HAS_ITERATOR_DEBUGGING
	void _Compat(const _Myt& _Right) const
		{	// test for compatible iterator pair
		if (this->_Mycont == 0 || this->_Mycont != _Right._Mycont)
			{
			_DEBUG_ERROR("vector iterators incompatible"); // line 238
			_SCL_SECURE_INVALID_ARGUMENT;
			}
		}
 #endif /* _HAS_ITERATOR_DEBUGGING */

I assume I could somehow disable iterator debugging to get around this error, but I would like to know why I'm getting the error in the first place. Am I doing something wrong? The iterators both come from the same vector object, so how could they be incompatible?

Phil

Anthony Appleyard20-Dec-07 10:43

Re: Class/struct declarations and bit patterns

20-Dec-07 10:43

In a class or struct declaration in Visual C++ 2008, for example

class BMPheader{public: char BM[2]; long size; short u,v; long imagestart;};

or

struct BMPheader{char BM[2]; long size; short u,v; long imagestart;};

can I trust on that being an accurate description of the resulting byte pattern inside the computer, to match the format of a binary file that is read in? My experience here is:

Gnu C++ for DOS: no, because after each element was inserted 0 or 1 or 2 or 3 unused bytes, to get each byte to start at an address which was a multiple of 4, unless I inserted a special keyword to tell the compiler to pack the elements close.

Borland C++ 4.5 for Windows: yes.

CPallini20-Dec-07 11:19

Re: Class/struct declarations and bit patterns

20-Dec-07 11:19

You have not to worry about alignment, as far you are consistent on writing to and reading from file, for instance (error handling left to the reader)

struct BMPHeader bmphout;
// assign struct members
...
FILE * fpout = fopen("foo.bin", "wb");
fwrite( &bmphout, sizeof(bmphout),1, fpout);
fclose(fpout);

and then

struct BMPHeader bmphin;
FILE * fpin = fopen("foo.bin", "rb");
fread( &bmphin, sizeof(bmphin),1, fpin);
// Now bmphin contains exactly the same data of original bmphout
fclose(fpin);

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

[my articles]

Anthony Appleyard20-Dec-07 11:56

20-Dec-07 11:56

But here I am reading from a file format which someone else (probably at Microsoft many years ago) invented. So I need to know how to make Visual C++ 2008 compile a struct or class with the elements in the same order as declared with no extra bytes inserted between.

Good Luck!

CPallini20-Dec-07 12:45

Re: Class/struct declarations and bit patterns [modified]

20-Dec-07 12:45

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

[my articles]

Mark Salsbery20-Dec-07 13:22

Mark Salsbery

20-Dec-07 13:22

Anthony Appleyard wrote:
But here I am reading from a file format which someone else (probably at Microsoft many years ago) invented.

Why are you not using the Microsoft structure definitions
that have been around just as long?

BITMAPFILEHEADER is packed with 2-byte alignment
BITMAPINFO and BITMAPINFOHEADER are packed with 1-byte alignment.

To see how that affects struct padding and alignment, see

align (C++)[^]
/Zp (Struct Member Alignment)[^]
etc...

If you're going to redefine these structs and expect them to match
everyone else, then you'll probably want to set your structure packing
the same as Microsoft's (see #pragma pack).

*edit*  Also, using platform-specific types like "long" and "short" is a bad<br />
idea if you expect to match the Microsoft definitions.

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

modified on Thursday, December 20, 2007 7:40:28 PM

After a picture is tranformed by GDI+, mouse cursor point problem

followait20-Dec-07 5:57

followait

20-Dec-07 5:57

Like DPtoLP, how to do it with GDI+,
use TransformPoints?

Re: After a picture is tranformed by GDI+, mouse cursor point problem

CPallini20-Dec-07 10:16