Is #include <../header.h> a bad practice in C++?

Question

My c++ project in summary is composed of two directories and of course the main.cpp:

Dataloader containing dataloader.h and dataloader.cpp
Analysis containing analysis.h and analysis.cpp

in dataloader.h I included analysis.h as follows:

#include<../Analysis/analysis.h>

My professor told me that it's a BIG NO NO!!!!!. We were trying to create a makefile and he was surprised. Why is it a bad practice? and how can I make the include simpler. I am working on code::blocks and gcc 4.8 compiler.

N.B. I noticed that code::blocks some how forgives include errors. When we tried to compiled it by using gcc command it went bad

What reason did he give you? Off-hand I don't see anything wrong with this. — Borgleader, Mar 26 '15 at 20:44
If anything lose the `../` ... then it should probably be fine. — l'L'l, Mar 26 '15 at 20:45
One more thing to consider is: http://stackoverflow.com/a/21594/499581 — l'L'l, Mar 26 '15 at 20:53
Usually a software under version control has a fixed file structure, or at least fixed relative path two or three directories above, so I think this is at least common practice among a lot of projects. — user3528438, Mar 26 '15 at 20:54

score 2 · Accepted Answer · answered Mar 26 '15 at 20:47

2

I agree with your professor. Use of

#include<../Analysis/analysis.h>

makes the code brittle. If the code base is re-organized using a different directory structure, files containing such #include statements will fail to compile.

Regarding:

N.B. I noticed that code::blocks some how forgives include errors. When we tried to compiled it by using gcc command it went bad

Add -I. to the compiler flags to resolve that problem.

answered Mar 26 '15 at 20:47

R Sahu

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actually it failed to compile when we were creating the makefile and compiling it with gcc command. Code::blocks is really forgiving makes work harder later. In the end it worked but wasn't satisfied with the include. thank you for your answer – Hani Goc Mar 26 '15 at 20:49

score 1 · Answer 2 · answered Mar 26 '15 at 20:52

Well I've always been taught, and this makes sense, that you should put your includes in the file that depends on them.

So in your situation, I assume you use dataloader to import data, and then the analysis to analyze it. Well in this case, it makes more sense to include both of these in the main.

In comparison, I made an n by n tic tac toe game that includes a print_board() function. This function relies on a header file with constants, colors.h, to properly print the board. So in this circumstance, it makes more sense for my print_board.h file to include the colors.h file, because it is directly dependent on it, and nothing else is.

Is #include <../header.h> a bad practice in C++?

2 Answers2