Re: MACRO vs INLINE FUNCTION - C / C++ / MFC Discussion Boards

Re: Edit Box and the Enter/Return Key

sweep12325-May-04 6:42

sweep123

25-May-04 6:42

The Multi-line was set to false.

If set that to true would that have sorted out the problem?

Re: Edit Box and the Enter/Return Key

David Crow25-May-04 8:25

David Crow

25-May-04 8:25

sweep123 wrote:
If set that to true would that have sorted out the problem?

That's ultimately up to you to determine. All I can do is suggest what the docs indicate, namely that when a multiline edit control is in a dialog box, the default response to pressing the ENTER key is to activate the default button. To use the ENTER key as a carriage return, use the ES_WANTRETURN style.

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Re: Edit Box and the Enter/Return Key

sweep12325-May-04 21:34

sweep123

25-May-04 21:34

Thanks for the info.

One effect I have with the use of the Edit Box is that if the user presses the Tab key when the Edit Box has focus then that is taken as an Enter key press.
This is with the Tabstop set to both true or false.

Note I set the Edit Box to read only until data input is expected, then its set to false and back again to true following the data entry.

Re: Edit Box and the Enter/Return Key

David Crow26-May-04 2:16

David Crow

26-May-04 2:16

sweep123 wrote:
One effect I have with the use of the Edit Box is that if the user presses the Tab key when the Edit Box has focus then that is taken as an Enter key press.
This is with the Tabstop set to both true or false.

This is not normal (i.e., default) behavior, unless you are doing something special with the VK_TAB key.

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

MACRO vs INLINE FUNCTION

avenger_sb2525-May-04 4:48

avenger_sb25

25-May-04 4:48

Hi geeks,

Please tell me when to use a MACRO and when to use an INLINE FUNCTION in C++. If this question has been asked before, please point me to that link.

I need an answer comparing the two. Please dont post definitions of macro and inline function as i am aware of them. Please give the answer in terms of efficiency, speed, code-size, pre-compilation/post-compilation, and things like that.
And please give examples ... Rose | [Rose]

...Avenger

Remember... testing & debugging are always part of programming ...so exterminate those stinking bugs

Re: MACRO vs INLINE FUNCTION

Maximilien25-May-04 4:53

Maximilien

25-May-04 4:53

always use inline ( or ordinary methods ).

the only reason I can give is that macros are preprocessor stuff and are not "debuggable"

Maximilien Lincourt
Your Head A Splode - Strong Bad

Re: MACRO vs INLINE FUNCTION

David Crow25-May-04 5:48

David Crow

25-May-04 5:48

Maximilien wrote:
the only reason I can give is that macros ... are not "debuggable"

That should be reason enough. Very few things should exist as a preprocessor macro. The ability to type-check parameters is a must.

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Re: MACRO vs INLINE FUNCTION

Curi0us_George25-May-04 6:32

Curi0us_George

25-May-04 6:32

My general rule is that if it can be done as an inline function, it should be.

There are some things which cannot be done with an inline function, but can be done with a macro. Those are rare, though.

Re: MACRO vs INLINE FUNCTION

Gary R. Wheeler25-May-04 15:04

Gary R. Wheeler

25-May-04 15:04

avenger_sb25 wrote:
Hi geeks,

That's a wee bit rude, don't you think?

avenger_sb25 wrote:
I need an answer comparing the two. Please dont post definitions of macro and inline function as i am aware of them. Please give the answer in terms of efficiency, speed, code-size, pre-compilation/post-compilation, and things like that.
And please give examples ...

This sounds suspiciously like you've got a take-home exam in a programming course, and you're looking for us 'geeks' to provide the answers.

I'll give you the answer to your question. My rate is $75USD/hr (you're getting the student discount, BTW), 4 hours minimum, in advance, in cash.

Software Zen: delete this;

Re: MACRO vs INLINE FUNCTION

avenger_sb2525-May-04 17:48

avenger_sb25

25-May-04 17:48

Is that something you say when you dont know the answer Mr?

Anyway a proper answer would have been appreciated. I was asked this questionj at a job interview. When i will get the job, i will pay u. LOL

...Avenger

Remember... testing & debugging are always part of programming ...so exterminate those stinking bugs

size of an empty class??

avenger_sb2525-May-04 4:41

avenger_sb25

25-May-04 4:41

Hi einstines,

i was asked this question at an interview:

class a<br />
{<br />
};<br />
main()<br />
{<br />
cout<<sizeof(a);  //WHATS THE OUTPUT?<br />
}

I can obviously run the program to find the output but i need an explanation about the output.

PLEASE ANSWER: WHAT IS THE OUTPUT????

...Avenger

Remember... testing & debugging are always part of programming ...so exterminate those stinking bugs

Re: size of an empty class??

jmkhael25-May-04 4:53

jmkhael

25-May-04 4:53

i did just that in VC++

class A
{
};

int _tmain(int argc, TCHAR* argv[], TCHAR* envp[])
{
int i = sizeof(A);
cout << "Sizeof A:" << i << endl;
}

it displayed 1.

I switched to assebmly listing and the linker has generated the following code:

77: int i = sizeof(A);
004018AB mov dword ptr [i],1 <----- Notice here, the linker knew its an empty class and automatically replaced its size by 1
78:
79: cout << "Sizeof A:" << i << endl;
004018B2 mov esi,esp
004018B4 mov edx,dword ptr [__imp_?endl@std@@YAAAV?$basic_ostream@DU?$char_traits@D@std@@@1@AAV21@@Z
004018BA push edx
004018BB mov edi,esp
004018BD mov eax,dword ptr [i]
004018C0 push eax
004018C1 mov ebx,esp
004018C3 push offset string "Sizeof A:" (004130d4)
004018C8 mov ecx,dword ptr [MSVCP60D_NULL_THUNK_DATA (00415234)]
004018CE push ecx
004018CF call dword ptr [__imp_??6std@@YAAAV?$basic_ostream@DU?$char_traits@D@std@@@0@AAV10@PBD@Z (004
004018D5 add esp,8
004018D8 cmp ebx,esp
004018DA call _chkesp (004014bc)
004018DF mov ecx,eax
004018E1 call dword ptr [__imp_??6?$basic_ostream@DU?$char_traits@D@std@@@std@@QAEAAV01@H@Z (0041523c)
004018E7 cmp edi,esp
004018E9 call _chkesp (004014bc)
004018EE mov ecx,eax
004018F0 call dword ptr [__imp_??6?$basic_ostream@DU?$char_traits@D@std@@@std@@QAEAAV01@P6AAAV01@AAV01
004018F6 cmp esi,esp
004018F8 call _chkesp (004014bc)

Papa

while (TRUE)
Papa.WillLove ( Bebe ) ;

Re: size of an empty class??

avenger_sb2525-May-04 5:01

avenger_sb25

25-May-04 5:01

Ya, thanx for ur reply and to tell the technique to see linker output Wink | ;)

(thats a new thing i learnt)

But, why 1? is it property of the linker or a C++ standard to make size of an empty class as 1. Please tell.

...Avenger

Remember... testing & debugging are always part of programming ...so exterminate those stinking bugs

Re: size of an empty class??

jmkhael25-May-04 5:10

jmkhael

25-May-04 5:10

Never tested it on unix, but one thing im sure of, is that empty structs are forbidden if you compile the file as a c file and not as a cpp.

However while permitting generation of an empty class, the linker is forced to allocate some space for it (vtable ...) and cos its empty, sizeof just returned the minimal size reserved for a class.

Papa

while (TRUE)
Papa.WillLove ( Bebe ) ;

Re: size of an empty class??

Curi0us_George25-May-04 6:38

Curi0us_George

25-May-04 6:38

VTable is only allocated if the class actually contains virtual functions.

The size of an empty class will always be greater than zero because two objects must not occupy the same space. (As DavidCrow pointed out)

Re: size of an empty class??

David Crow25-May-04 5:57

David Crow

25-May-04 5:57

avenger_sb25 wrote:
WHAT IS THE OUTPUT????

It won't be zero, as that would allow two different objects to have the same address. If sizeof(a) returned 0, then the following would be allowed:

main()
{
    a a1, a2;
    if (&a1 == &a2)
        ... // if we get here, the compiler is faulty
}

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Re: size of an empty class??

Nemanja Trifunovic25-May-04 6:01

Nemanja Trifunovic

25-May-04 6:01

From the Standard (1.8.5)

Unless it is a bitfield, a most derived object shell have a non-zero size and shell occupy one ore more bytes of storage. Base class sub-objects may have zero size.

Re: size of an empty class??

avenger_sb2525-May-04 17:46

avenger_sb25

25-May-04 17:46

Base class sub-objects may have zero size

Can u please give a working example. I did

class p<br />
{<br />
};<br />
class q: public p<br />
{<br />
};<br />
p o1;<br />
q o2;<br />
	cout<<sizeof(o1);<br />
	cout<<sizeof(o2);

I get 1 in both. Thank you.

...Avenger

Remember... testing & debugging are always part of programming ...so exterminate those stinking bugs

menu next to images

Member 466743725-May-04 4:34

Member 4667437

25-May-04 4:34

how do i place a image next a menu

Clint

Re: menu next to images

jmkhael25-May-04 4:43

jmkhael

25-May-04 4:43

What about this[^]

Papa

while (TRUE)
Papa.WillLove ( Bebe ) ;

Re: menu next to images

Member 466743725-May-04 9:26

Member 4667437

25-May-04 9:26

thank you for your reply but, these examples are all part of the toolbar not nex to the toolbar.

Clint

Re: menu next to images

Maximilien25-May-04 9:30

Maximilien

25-May-04 9:30

huh ?

what exactly do you want ? a popup/drop down menu in a toolbar ?

Maximilien Lincourt
Your Head A Splode - Strong Bad

Re: menu next to images

Member 466743726-May-04 11:14

Member 4667437

26-May-04 11:14

something that looks like a standard menu ie File,edit,options but can have a large picture, on the left which may, or may not overlap the toolbar.

Clint

Question about Saving Fonts.

Mike Doner25-May-04 4:15

Mike Doner

25-May-04 4:15

I have a quick question regarding saving font settings in a drawing type package.

For example, an application like Corel Draw who has a TextBox on the canvas who uses Arial font, how would that information be saved?

Obviously, we'd store the text in some kind of string/char object, but for the font, would you just store the szFontName, nPointSize and some style bits (bold/italics/underline)?

We're working on an issue with our product where somebody has chose to save the LOGFONT structure, but we're finding that the logfont.height guy is based on the DC because of the call:

logfont.lfHeight = -MulDiv ( PointSize, GetDeviceCaps(hdc, LOGPIXELSY), 72 );

Bottom line, Whats the common way to save this stuff?

Any info you could send would be greatly appreciated.

Mike.

Re: Question about Saving Fonts.

Johan Rosengren25-May-04 21:28

Johan Rosengren

25-May-04 21:28

I would save the font height in typographical points - that is, PointSize rather than logfont.lfHeight above.

You might want to consider using CreatePointFontIndirect for font creation, then you can save/load the LOGFONT directly.

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