[Webinar] Streamline your web hosting managementRegister Today

x
?
Solved

Templates and multiple-file projects

Posted on 2004-10-12
5
Medium Priority
?
587 Views
Last Modified: 2012-06-27
How can I handle Templates in multiple-file projects? Please explain...

0
Comment
Question by:msjammu
5 Comments
 
LVL 86

Accepted Solution

by:
jkr earned 500 total points
ID: 12288635
You need to provide the template implementation in the header files and include them in each file. Even though the C++ standard would allow to separate the implementation from the declaration, there's no compiler out there that can handle that.
0
 
LVL 12

Expert Comment

by:stefan73
ID: 12289339
Hi jkr,
g++ had something close with its #pragma interface and #pragma implementation. I think this was abandoned in the 3.x versions.

The problem is always that multiple instances of template methods or functions are created and must be discarded by the linker - otherwise the final executable would be totally bloated.

Some compilers, such as SUN's CC, create temporary directories to counter the problem. As long as the directory where you compile your files is the same for all involved .cpp or .C files, there are no multiple instances created.

Cheers!

Stefan
0
 
LVL 6

Author Comment

by:msjammu
ID: 12295163
Stefan,
you mean with g++ I can have templates with my multi-files project, with no problems?
I use VC++ 6.0 SP6. Does not it seam to support it??

Many Thanks !
0
 
LVL 39

Assisted Solution

by:itsmeandnobodyelse
itsmeandnobodyelse earned 500 total points
ID: 12300303
jkr has it right. If you want to provide easy-to-handle template classes put all implementation to the header files (directly in the class definition or as inline functions) that should be stored to a shared project directory (you may add that direcory to Tools-Options-Directories-Include Files or to the 'Additional Project Include Directories' in Project Settings). Then, by simply including the class headers you may use these templates in multiple projects.

All other solutions are much less flexible or differ between Platforms/Compilers, e. g. you can move class implementation to cpp files, *but* need to have separate cpp sources where you make instances of your template classes for any type you are using. There you have to include the cpp files (!) of your template class implementation. Some Compilers also have #pragma interfaces that were able to create template instances (the template code for a specific type).

Regards, Alex
 
0
 
LVL 6

Author Comment

by:msjammu
ID: 12305317
Thank Your all experts for there help
0

Featured Post

The new generation of project management tools

With monday.com’s project management tool, you can see what everyone on your team is working in a single glance. Its intuitive dashboards are customizable, so you can create systems that work for you.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Many modern programming languages support the concept of a property -- a class member that combines characteristics of both a data member and a method.  These are sometimes called "smart fields" because you can add logic that is applied automaticall…
Container Orchestration platforms empower organizations to scale their apps at an exceptional rate. This is the reason numerous innovation-driven companies are moving apps to an appropriated datacenter wide platform that empowers them to scale at a …
The goal of the tutorial is to teach the user how to use functions in C++. The video will cover how to define functions, how to call functions and how to create functions prototypes. Microsoft Visual C++ 2010 Express will be used as a text editor an…
The viewer will learn how to pass data into a function in C++. This is one step further in using functions. Instead of only printing text onto the console, the function will be able to perform calculations with argumentents given by the user.

591 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question