It's surely a noobish problem, I'm sorry for wasting your time, but I can't find any solution (I searched a bit on the internet, but found nothing).
I have a Console Application Project in Visual Studio 2013 and I have many folders where I put various .h and .cpp files. In these files I use namespaces for grouping classes.
The problem is that I can't include headers that are in parent directories in the current .cpp or .h file.
For example, I have a Hello class under the path /a/b/c, that is included in the namespace A/B/C, and a Hi class under /a/b/ that is in the namespace A/B. In my situation the Hello class doesn't "see" class Hi, but class Hi can "see" class Hello. Also, if I have Bye class in folder a/d/ with namespace A/D, class Bye doesn't "see" class Hi and Hello, and viceversa.
What I mean for "doesn't see" is that #include doesn't find the headers and that when I use "using namespace ..." there aren't parent namespaces.
P.S. I hope my English is understandable (it's not my mother language) and that what I just wrote above is clear.
In the Solution Explorer Window. Right click on your project and choose Properties from the menu.
In the C/C++ -> General settings the first field is "Additional Include Directories"
This is where you add paths for the compiler to load include files.
When the compiler encounters an #include statement, it tries to open the specified file. If the file is an absolute path, it only tries to load from that specific absolute.
If the file is a relative path, it tries to load from the directory of the file being compiled first. If the file is not found in the same folder as the c/cpp file, the compiler tries each of the paths in its 'Include Directories' list to find the file.
In visual studio, the 'Additional Include Directories' are based on the current project directory by default. You can obviously specify whatever you want using absolute paths and/or variables.
For your example you might want include directories something like:
a/b;a/b/c;a/d
I found a solution for the problem. I used as a prefix in my #include the string "../../", then I can include all my files in my directories. I don't know if this the best thing to do, but it worked.
Related
I previously had all of my source files in the same folder just scattered about, but I was getting tired of the disorder, so I created a folder hierarchy and organized my headers and .cpp files in those folders, and changed the ClInclude tags in the projects .vcxproj file accordingly. I then changed all the #include rows in the source headers to match the new location of the headers.
Now when I compile I get a heap of errors saying that the namespace "math" can't be found. The namespace could be found before the file organizing, so the problem should be something with that, but that #includes works fine.
If I write
using namespace
the autocomplete finds the namespace just fine, and no red wiggly lines show up in the text interface.
I'm using VS17 Community.
There are actually two ways to resolve your issue. You've already noted the first, that you can always use relative paths (relative to the source file).
#include "..\Math\math.h"
This will work just fine. You can also modify your C++ Project Properties to add a list of include directories. This will be very useful for you when you begin working on projects that use a lot of libraries To add include directories you need to:
right-click on your project in the solution explorer and select Properties.
In the left pane, click on the C/C++ > General tab.
On the property that says Additional Include Directories, click the drop down arrow (you may need to click inside the text first) and select Edit...
From here, you can add a list of include directories that you will be using with your project. You can use:
Absolute Paths
C:\Path\to\Math
Relative Paths (relative to your .vcxproj file)
..\..\relative\path\to\Math
Macros (Visual Studio will list your available macros)
($SolutionDir)..\path\to\Math
You'll see the use of the macros a lot when it comes to C++ and other Visual Studio projects not just for include directories, but for build events as well.
Once you've added a list of include directories, you can go back to including your headers in the source code as normal:
#include "math.h"
In the event you need to use a relative path from one of your included folders, you can do that as well.
// some directory inside of Math
#include "MoreMath\moremath.h"
// some directory above Math
#include "..\AboveMath\abovemath.h"
Hope this helps!
I solved it...
Remove this question if necessary. The problem was that I didn't backtrack the filepath in my #include "math.h". They should instead have said #include "..\Math\math.h".
I started coding in C++ few days ago. I am using windows as my OS for writing code. I have been keeping all of my "well-written" codes in a single location. Now, I am working on a project that requires the use of those codes. So, I planned to include those files that I require as header files in my project. However, to make my project "self-contained", I created shortcuts of those folders that I require and kept them in the source folder of my new project and decided to use relative paths to the shortcuts in the "include" statements in my project.
However, I am getting an error. Is there any way to use relative (or, in general, absolute) paths to shortcuts in the include statements of C++ in windows?
Thanks.
It really depends on how you include the header files.
If you include with double-quotes, like e.g.
#include "some_header_file.h"
Then the relative path is from the current files location.
If you include using angle-brackets, like e.g.
#include <some_header_file.h>
Then the relative path is based on the system include paths.
You can always add a path to the system include path. How to do it depend on your environment and compiler. If you're using Visual Studio you go into the project properties dialog, and in the "C/C++" / "General" tab there is a field called "Additional Include Directories" where you can add directories. (This is for VS 2015, might be a little different on other versions.)
Regarding double quotes inclusion. Lets say your project hierarchy looks like this (on disk!):
Project
|-- Include
|-- Source
| `-- MoreSource
`-- Other
In Project/Source you have your source files, and if one of them want to include a header file from Project/Include, then it will look something like
#include "../Include/header.h"
Now if you have a source file in Project/Source/MoreSource that want to include the same header file it will be
#include "../../Include/header.h"
It could be useful to add the Project/Include directory to the system header search path. You can still use double-quotes to include the files, since if they are not found then the preprocessor will search the system paths as well, but you don't need the "full" relative path. If you add Project/Include to the system header path, you could write just
#include "header.h"
Or
#include <header.h>
Be careful though, if you have a header file with the same name as an actual system header file you might have some trouble.
From https://superuser.com/questions/253935/what-is-the-difference-between-symbolic-link-and-shortcut
You can't include folder shortcut since it's a file, not a folder.
You can read the guide to create symbolic link on windows.
I've been searching for how to do this for nearly an entire day.
At first, I thought that this can be done by...
Right click the project name -> "Add files" -> choosing a .cpp file which contains the class you need and the corresponding header file.
Then, the .cpp file and header file appeared with its original folder. After this, I wrote #include"random.h" on the project which needed to use random.h and its functions.
However, this produces an error, indicating that fatal error: random.h: No such file or directory. The compiler apparently can't find the file (even though I can).
I add a picture of this.
Also, I've been looking for how to add .cpp & header files without its folder.
(In the picture above, for example, you'll see that random.cpp inside Using_a_class_test is included in a folder named Random. To my shame, I haven't found how to eliminate such a folder.)
I'd appreciate if you'd offer any insight.
Unfortunately, what you did is not enough. When you try to compile
#include "random.h"
The compiler needs to know where the random.h file is, and for that it uses the include path info, which is unrelated to the files you included in the project.
A couple of solutions:
You modify all occurrences of #include "random.h" to be #include "/path/to/random.h"
You modify the include path information for your project. Go to Project >> Build options, select the tab "Search directories" and add all the paths to your .h files there.
Hope this helps.
I want to include a specific header file (MyHeader.h) in a C++ project. The solution for my project is located in the folder:
C:\\Projects\\MyProgram
The header file is located in the folder:
C:\\Projects\\MyProgram\\Files
I tried the following line of code, but it doesn't work.
#include <Files\MyHeader.h>
Is there an easy way to include the header file without adding the full path to "Include directories" in the configuration properties?
Thanks in advance for any help. :)
Try this
#include "files/myheader.h"
It will work if the header is in a files folder in the same directory as the current source.
If you're trying to include a 3rd party library and not your own header, I'd suggest you to save the library headers in a particular path (say C:\Library\headers). (If there are static libraries put them in some other path like C:\Library\lib).
In your Visual Studio C++ Project, go to View > Other Windows > Property Manager.
Double Click on the Project Name. You will see a dialog box like this:
Make sure All Configurations is chosen in the dropdown, if you want the change to be applied to both the Debug and the Release Configurations. Else just choose the Configuration you want the properties to be applied to.
Go to VC++ Directories on the left and choose Include Directories in the right, and enter the path(s) in the textbox separated by a ;.
You can also use the drop down and use the Dialog box to add the paths if you'd prefer to browse to each path separately
Add the library path the same way to Library Directories
Save the changes using the Save button on the Property Manager Pane's toolbox.
You will then be able to access the header file contained in the directory you added by something like:
#include <myheader.h>
This approach will help, because it won't matter where the headers saved. The header path is not hard-coded.
The current directory of the source file is always searched, although if you use angled brackets it is searched after your include path, whilst if you use quotes it will be the first directory searched.
The directory of your solution or makefile/project file is irrelevant, the local path is relative to the compilation unit, i.e. the cpp file.
If that cpp file includes a header, that headers own includes are relative to itself, not the cpp file that included it. (It would be hell to manage if it were not).
Ideally you should use forward slashes in paths too.
Your actual correct setup here is to include the solution directory in your search path. If it is Visual Studio you can use a macro for this, $(SolutionDir) I think.
That means that if anyone else is going to build your solution, they can put it in a directory they choose and as long as the structure underneath is the same, it will still work.
To use a relative path in your cpp file without any include directory settings, you might need something like:
#include "../Files/MyHeader.h"
You just need to replace your brackets <> with double quotes "" like this:
#include "Files\MyHeader.h"
Brackets is used when you want Visual Studio to find the path from your project settings and double quotes when you want to access the header from a specific path or relative to your project.
I'm using VS2010 (downloaded via dreamspark) and although I can open the #include file by right clicking on it and pressing on Open Document, it complains "Error can not open source file "..."" which seems rather absurd. I'm using Qwt with Qt this time around and I'm specifically having the problem for:
#include <qwt_counter.h>
#include <qwt_plot.h>
(And I am using the "<>"); not sure how to make those appear properly in the code above.
Thanks in advance.
As Neil indicated, try using quotes instead of the <> characters around the filename. When using the quotes, MSVC will look in the same directory as the file the #include is in for the specified file, then if it's not found there will look in the directories specified by the include path. When the filename is surrounded by <> characters, the current file's directory isn't looked at - the compiler goes right to the include path.
See http://msdn.microsoft.com/en-us/library/36k2cdd4.aspx for details.
Note that this is an implementation dependent behavior - it might not apply to other compilers.
If that doesn't help, make sure that your include path contains the directory that the file is located in by setting the "Include Directories" property appropriately:
http://msdn.microsoft.com/en-us/library/t9az1d21.aspx
Finally, you might be using a makefile project (I'm not sure how common it is for Qt projects to continue to use qmake when built from VS) , in which case you'll need to perform whatever configuration is necessary in the make file(s) or parameters passed on the command line that invokes the makefiles.
Is the path where these files are located either the same as that of this source file, or included in the "additional include directories" in your project settings?
Project -> properties -> c/c++ section -> additional include directories.
If they are located in a subdirectory of the source file you're editing or of one of the additional include directories (I think) you can also include them with:
#include <path_to_file_1/qwt_counter.h>
#include <path_to_file_2/qwt_plot.h>
[edit]
or of course what neil says
[/edit]
It turned out there was a circular linking happening and I had all my code in a .h file. I split it up and added the corresponding .cpp file, now everything works fine.