undefined reference to constructors and destructors

[avinash6174]

I could complie my code in one directory and the same piece of code in the other directory I couldnt complie the code..

I am working on the same machine ..

Its giving an eror saying as undefined reference to constructors and destructors.
I have checked the permissions of the directory also ..both are same..

complier I am using is g++
and operating system is linux..

could anyone help me out in solving this error..
Thanks in advance..

[gpraghuram]

I could complie my code in one directory and the same piece of code in the other directory I couldnt complie the code..

I am working on the same machine ..

Its giving an eror saying as undefined reference to constructors and destructors.
I have checked the permissions of the directory also ..both are same..

complier I am using is g++
and operating system is linux..

could anyone help me out in solving this error..
Thanks in advance..

R u using multiple files...If yes have u copied all the files to the new directory?

Raghuram

[avinash6174]

R u using multiple files...If yes have u copied all the files to the new directory?

Raghuram

I have copied the directory by cp -r olddirectory newdirectory.....
but still not working....

[weaknessforcats]

You say it's a compile error.

The only way you get an unresoved reference at compile time is when the header file can't be located.

Since you have moved the files, the project is expecting the files in the original location.

When you #include <MyHeader.h> the preprocessor looks for the file in a sstandard place.
A standard place is a predefined path. Typically, there will be project settings where you can specify
the path (or paths) the preprocessor as additional include directories. The preprocessor will
search for your header file in the order of the specified paths.

When you #include "MyHeader.h" the preprocess looks for the file in the present working directory (PWD).
Typically, this is the folder that contains the project file itself. If the header file is not found
there, then the search continues as though you had coded #include <MyHeader.h>.

This allows you to make a copy of a header file and #include "MyHeader.h" so you can makes changes to it
without garbaging the original. Any code that #include <MyHeader.h> will use the original file
and will not see your revisions. After you have debugged you changes you can copy the revised header back
to the original folder.

Now of this is a linker error, then you are missing some source files in your build or have failed to include a libraary in your makefile as an additional linker dependency.