|
|
This may be trivial for most of you. I have been programming for about 20 years, now, I have a Computer Science degree, and I have never had any one define, for me, what a wrapper is. I am sure I have probably made them and used them without knowing that is what they are called. To me a wrapper is that little bit of paper I have to go through to get to a piece of gum. Can someone tell me what is meant, in the programming world, by the term wrapper?
|
|
|
|
|
To me, from an object-oriented point of view - there's the concept of Encapsulation[^].
A wrapper provides the "capsule" for encapsulation.
For example, a wrapper class provides a public interface to a hidden/private implementation.
My 1 cent.
Mark
p.s. I don't know if the article I linked to is good - I just know it saved me some typing 
"Posting a VB.NET question in the C++ forum will end in tears." Chris Maunder
|
|
|
|
|
MFC can be compared to a Wrapper AROUND Win32 calls; it makes creating and managing UI (mostly) easier for the programmers.
Wrapper functions or classes are created to make API simpler to use.
|
|
|
|
|
huehue wrote: To me a wrapper is that little bit of paper I have to go through to get to a piece of gum
I think you've found your way.
More specifically (but informally), we usually talk about Wrappers only in OOP. For instance MFC builds objects (wrappers) around plain C API. Wrapper is a broad concept of OOP, you can find specialized applications of this concept (for instance) in Proxy, Facade, Adapter design patterns.
hope that helps
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.
|
|
|
|
|
A wrapper is some code or object which simplifies or adapts the use of some service by isolating the user from the complexities/specifics of its interface; often providing a simpler or more portable interface. Conceptually it "wraps" around the old interface.
Steve
|
|
|
|
|
This helps, thanks guys...
|
|
|
|
|
I’m working in a big MFC application. I now have Several Forms to add into this application. The original developer says there is no reason to stick with MFC. So I need to convert this MFC application. I’m looking for websites and/or books on converting. Both the old and new application will need to be written in C++.
Any advice would help.
Thanks
Programmer
Glenn Earl Graham
Austin, TX
|
|
|
|
|
If it's not broken, don't change it.
question to ask yourself :
Will that change bring an additional value to your development process in the short, medium and long term
Can you spend the time doing Research to do this ? Can you spend the time to do the additional development ?
|
|
|
|
|
|
I have it on order. Thanks
Programmer
Glenn Earl Graham
Austin, TX
|
|
|
|
|
Hi, I am using Visual Studio 2005, I build new win32 console application project and I tried to compile this simple code
<br />
#include "stdafx.h"<br />
#include <iostream><br />
<br />
int _tmain(int argc, _TCHAR* argv[])<br />
{<br />
using namespace std;<br />
char question[] = "Please, enter your first name: ";<br />
char greeting[] = "Hello, ";<br />
char yourname [80];<br />
cout << question;<br />
cin >> yourname;<br />
cout << greeting << yourname << "!";<br />
return 0;<br />
}
But I get error of
error LNK2019: unresolved external symbol "__declspec(dllimport) class std::basic_ostream<char,struct std::char_traits<char> > &__cdecl std::operator<<<char,struct std::char_traits<char> >(class std::basic_ostream<char,struct std::char_traits<char> > &,char const *)" (__imp_??$?6DU?$char_traits@D@std@@@std@@YAAAV?$basic_ostream@DU?$char_traits@D@std@@@0@AAV10@PBD@Z) referenced in function _wmain
But when I comment out the line
it compile successfully.
I think there is library file missing, but don't know which one. I googled out so many website and still can't find out the solutions, any ideas how to solve this ?
Thanks.
-- modified at 1:33 Sunday 6th May, 2007
|
|
|
|
|
esia wrote: I think there is library file missing, but don't know which one.
Which ones are you linking with?
"A good athlete is the result of a good and worthy opponent." - David Crow
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
|
|
|
|
|
Thanks for your reply, I didn't link any library file, but when I read from this solved post where they include the path to msvcprt.lib, http://www.tek-tips.com/viewthread.cfm?qid=1354561&page=1
But when I did that, I still get the same error. Any ideas how ?
|
|
|
|
|
The following are the default libraries for a Visual Studio 2005 C++ Win32 Console application: kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib.
"We make a living by what we get, we make a life by what we give." --Winston Churchill
|
|
|
|
|
Thanks for your reply, but what you trying to explain to me ?
|
|
|
|
|
Are you using the /nodefaultlib compiler switch?
"A good athlete is the result of a good and worthy opponent." - David Crow
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
|
|
|
|
|
George L. Jackson wrote: The following are the default libraries for a Visual Studio 2005 C++ Win32 Console application: kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib.
But the relevant one is going to be one of:
libcmt.lib
msvcrt.lib
libcmtd.lib
msvcrtd.lib
msvcmrt.lib
msvcurt.lib
These are governed by the /nodefaultlib and /Mx compiler switches.
"A good athlete is the result of a good and worthy opponent." - David Crow
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
|
|
|
|
|
On VC++ 6.0 I need these to get that to compile and run...
#include <iostream>
#include <tchar.h>
// Not sure if that helps since I don't have Visual C++ 2005
|
|
|
|
|
bob16972 wrote: On VC++ 6.0 I need these to get that to compile and run...
#include <iostream>
#include <tchar.h>
// Not sure if that helps...
Especially since it's a linker error.
"A good athlete is the result of a good and worthy opponent." - David Crow
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
|
|
|
|
|
Fair enough. I was just hoping they had been tinkering to get errors to go away and they were posting the latest error which may have been after changing project settings around etc...
I didn't realize the include for iostream was there since they didn't check the "ignore HTML tags in this message" box. I saw your other post and took a look at the html source and there it is.
I was hoping that maybe by starting a new project and copying and pasting the code with the includes would fix it if they had messed with the project settings before posting the latest errors.
I would assume VC++ 2005 would give the correct basis for a crt project but maybe I'm mistaken. This thread may help spark some ideas for the original poster...
ideas and shots in the dark[^]
|
|
|
|
|
Include
#include <iostream> .
Regards,
Paresh.
|
|
|
|
|
Paresh Chitte wrote: #include <iostream>
It already is being included. Furthermore, it's a linker error, not a compiler error.
"A good athlete is the result of a good and worthy opponent." - David Crow
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
|
|
|
|
|
|
Sorry for the late of reply, actually I did include #include <iostream>, I forgot to convert the tag to the literal string, so the browser always treat the opening tag as html code. Ok but my problem has been solved when I changed the setting, Project > properties > C/C++ > Runtime Library > Multi-threaded Debug DLL (/MDd) . Does anybody knows why is it so ? I am using Visual Studio 2005 professional,
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
