C++ Header and Source Directories

Question

I have the following files:

listDriverTest.cpp
src/List.cpp
headers/List.h

The include in List.cpp is

#include "../headers/List.h"

The include in listDriverTest.cpp is

#include "headers/List.h"

When I compile with the following statement,

g++ listDriverTest.cpp "src/List.cpp"

I end up with a fair number of 'undefined reference' errors, e.g.

listDriverTest.cpp:(.text+0x81): undefined reference to `List<int>::List()'
listDriverTest.cpp:(.text+0x8f): undefined reference to `List<int>::add(int)'
listDriverTest.cpp:(.text+0x9d): undefined reference to `List<int>::add(int)'
...

How should I properly use includes and compile these three files in order for the compilation to work properly? I have gotten listDriverTest.cpp to compile and run properly with all the files in the same directory, but not when they're broken up like this.

I'm surprised you're not getting a very specific error related to the inability to find the list.h header. — Michael Wilson, Apr 16 '12 at 17:47
You need to define everything in header file when working with templates http://www.parashift.com/c++-faq-lite/templates.html#faq-35.13 — victor.t, Apr 16 '12 at 17:47
*Undefined reference* are linker errors, so it has few to nothing to do with your header/source locations. — David Rodríguez - dribeas, Apr 16 '12 at 18:09

score 1 · Accepted Answer · edited May 23 '17 at 10:08

1

See my answer in Must a child of a template class also be a template class?.

It is probably a different question, but the same answer applies.

edited May 23 '17 at 10:08

Community

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answered Apr 16 '12 at 17:46

d_inevitable

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Ah, thank you. I /completely/ forgot about the issue with having a header file and cpp file for template methods that belong to a class. That fixed the problem right up! – Tanaki Apr 16 '12 at 18:02

score 1 · Answer 2 · answered Apr 16 '12 at 18:00

It looks like the object file produced by compiling src/List.cpp already contains the specialization List, but it's in a different directory than the object file of listDriversTest.cpp. Hence, the linker cannot find it.

Of course, this depends on how you've organized your template code.

prathmesh.kallurkar · Answer 3 · 2012-04-16T17:56:27.157

0

Your program compiled properly on my machine.
Just remove the double quotes around src/List.cpp I think your problem is something else.

I added a function void list(void) in list.cpp which printed "list".
The same signature was added to list.h.

edited Apr 16 '12 at 17:56

answered Apr 16 '12 at 17:50

prathmesh.kallurkar

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C++ Header and Source Directories

3 Answers3