strcpy(this->encoding, jsonvalue.get("encoding", "").asCString());
I need to work with json data in my program, yesterday i downloaded it using nuGet, coded all i needed, commented path to jsoncpp.lib but system doesnt allow me to start the program due to missing jsoncpp.dll. Does this mean i need to take the dll everywhere with my program? If so, im not happy with that so can i solve this? Or if its impossible, which json libraries that doesnt require dll can i use ?
download amalgamation (all source is in one file)
add jsoncpp.cpp to your project
uncomment #define JSON_IS_AMALGAMATION in json.h
add #include "json/json.h" at the beginning of your source code
Please use the latest source-code. The project has moved to GitHub. cmake would probably solve your problem.
Related
Introduction
I am trying to use Toulbar2 as a C++ library in my CMake project, however I am having much trouble linking it to my main executable.
I found many similar questions on this topic, both here and on other similar website, but none of them helped me with my specific issue. I tried literally everything and I did not menage to make it work, I was hoping that some of you may help me with that.
I am running Ubuntu 18.04, CMake version 3.23 and in my project I am using the standard C++11. I am a proficient programmer, but I am just an beginner/intermediate user of both C++ and CMake.
What I've already tried to do
I cannot list all my attempts, so I will only mention those I think are my best ones, to give you an idea of what I may be doing wrong.
1) In my first attempt, I tried to use the same approach I used for any non-standard library I imported, i.e. using find_package() in CMakeLists.txt to then link the found LIBRARIES and include the found INCLUDE_DIRS. However, I soon realised that Toulbar2 provides neither a Find<package>.cmake or <name>Config.cmake file. So, this approach could not work.
2) My second attempt is the one that in my opinion brought me the closest to the solution I hoped for. You can easily compile Toulbar2 as a dynamic library using the command: cmake -DLIBTB2=ON .. in an hypothetical build directory you previously created. After compiling with make you have your .so file in build/lib/Linux. After installation, you can make CMake find this library by itself using the command find_library. So, my CMakeLists.txt ended up looking like this:
[...]
find_library(TB2_LIBRARIES tb2)
if(TB2_LIBRARIES)
set(all_depends ${all_depends} ${TB2_LIBRARIES})
else(TB2_LIBRARIES)
add_compile_definitions("-DNO_TB2")
message("Compiling without Toulbar2, if you want to use it, please install it first")
endif(TB2_LIBRARIES)
[...]
target_link_libraries(main ${all_depends})
[...]
This code works to some extent, meaning that CMake correctly finds the library and runs the linking command, however if I try to #include <toulbar2lib.hpp> the header is not found. So I figured out I should have told CMake where to find that header, so I ended up adding a
include_directories(/path/to/header/file's/directory)
However, I still have another problem. The header is found, but a lot of names used in the header are not found at compilation time. The reason is that in Toulbar2 some variables/types are defined conditionally by using preprocessing directives like #ifdef or #ifndef, and in turn the global variables used in these conditions are defined through CMake at compilation time. If you are interested in an example, I can mention the Cost type that is used in the mentioned header file. I see that there's a piece missing in the puzzle here, but I cannot figure out which one. Since I pre-compiled the library those definitions should exist when I include the header file, because I am correctly linking the correspondent library that contains those definitions.
3) My third attempt is less elegant than the the other two I mentioned, but I was desperately trying to find a solution. So, I copied the whole toulbar2 cloned folder inside my project and I tried to add it as a subdirectory, meaning that my main CMakeLists.txt contains the line:
add_subdirectory(toulbar2)
It provides a CMakeLists.txt too, there should be no problem in doing it. Then I include the src directory of toulbar2, that contains the header file I need, and I should be okay. Right? Wrong. I got the same problem that I had before with (2), i.e. some variables/types conditionally defined were not actually defined when I tried to compile my project, even though the subproject toulbar2 was correctly (no errors) compiled.
I just wanted to mention that any answer is welcome, however if you could help me figure out an elegant solution (see 1 or 2) for this problem it would be way better, as this code is intended to be published soon or later. Thank you in advance for your help.
Solution 2) looks fine. You just need to add the following compilation flags -DNDEBUG -DBOOST -DLONGDOUBLE_PROB -DLONGLONG_COST when compiling your project with toulbar2lib.hpp. See github/toulbar2 README.md how to compile without cmake for those flags (except WCSPFORMATONLY that should not by used in this context).
I am a C# developer, and spoiled rotten when it comes to references and dependencies. I am working on a small project now in Visual C++ (Visuial Studio 2017), where I want to use the libtomcrypt and libtommath libraries. I've created a small project and added the 2 projects to my solution:
I have also added my includes:
And I added the dependencies:
However, I still can't build:
Error C1083 Cannot open include file: 'tomcrypt.h': No such file or directory
I am not sure what else I need to do to get the references working and the code to compile. Any pointers is appreciated!
The error message indicates that the compiler can't find the file tomcrypt.h while compiling one of your source files. From the message I would guess that you have a line like the following in your source file:
#include <tomcrypt.h>
(...or perhaps with quotes instead of brackets.) From your screenshot I can see that you've added "...\repos\libtomcrypt-develop\src\headers" to your include path. Is the file tomcrypt.h found directly in that folder, or is it perhaps in a subfolder instead?
Your #include directive will basically append whatever path you give it to each entry in your include path when looking for the file, so if there are subfolders in between, you'll have to expand your #include directive to include those folders.
If this doesn't solve your problem, perhaps try posting the actual full path of where this header file exists on your filesystem, as well as your complete include path value! (The full compiler command from the build log would be useful, as well as the complete error message(s) related to this source file.)
Edit:
The original poster posted a separate answer indicating that the actual problem was that the Visual Studio Project Properties were set correctly, but that he was accidentally trying to build a different Configuration. :(
I was building the project under x86. Once I changed it to x64, it built just fine.
I recently downloaded a third party library called spline-master from github and the file provides a header file called spline.h. I wanted to use this header file so as to create a spline. I am currently using eclipse oxygen for c/c++. I was pretty new to this and have been stuck on this problem since the last few days. I tried changing so many things to link this file. The file can be seen in my project tree and it's there in the includes but when I write #include"spline.h" it throws me an error telling "there exists no such file or directory".
Can anyone please let me know how I can go about this problem? All the applications are of the latest version including Ubuntu. I would have attached a couple of screenshots so that you can have a better idea about the problem I am facingenter image description here
Thanking you.
Regards,
Sumanth
enter image description here
There are 2 main ways to include a header file, and you need to know where your spline.h is located in order to know which one you can use.
#include "spline.h"
Enclosing in quotes will tell the preprocessor that the path you have supplied is relative to the location of the code file you are including the file into. Your compiler can't find the file which means it must be located in a directory different to the code file you are working on.
#include <spline.h>
This is probably the version you want to use. This version will tell the preprocessor to look for spline.h in any header directories you have defined in your project. Again, it considers the path relative to the header directory.
I am trying to complete the Boost.DLL tutorial (http://www.boost.org/doc/libs/master/doc/html/boost_dll/tutorial.html)
However, I'm not able to even compile their source code, I keep getting:
fatal error: boost/dll/import.hpp: No such file or director
I tried manually copying the header files from the repository (https://github.com/apolukhin/Boost.DLL), but even when I copy these into "/usr/include/boost/" I get new errors from the same kind about "boost/predef/os.h".
I've tried reinstalling the complete boost library and everything, but without success.
Since they describe themselves as "Boost.DLL is a header only library. To start with the library you only need to include header"
It seems like there should be an easier way to fix this than go through the include-errors and manually search for the right files on the internet...
Right, I know this is a very stupid question, but I have no luck with w/e i'm trying to do.
I'm trying to use the objdetect.hpp header file, so I've included the folder C:\OpenCV2.1\include\opencv2\ aswell as C:\OpenCV2.1\include\opencv and a whole bunch of other libraries and dlls when I was following the instructions on http://opencv.willowgarage.com/wiki/VisualC%2B%2B_VS2010
But the openCV version in that tutorial were outdated and doesn't even have the objdetect.hpp file. So I went to download the latest one (OpenCV 2.4.0), but now when I complie it, it gives me an error C1083: Cannot open include file: "opencv2/core/core.hpp" No such file directory.
Am I suppost to put all the OpenCV folders/files in the same directory as my C++ project? Or how do I fix it? I've tried putting it in the same place as my C++ project, but when I do a #include "../" the folder doesn't appear.
Again, I know this is a stupid question, but please help.
Let me know if anyone require more info coz I'm not too sure whatelse to put.
Thanks
The best way to manage changing directories for include files is with the compiler options. Im better at linux and g++, where you would just specify different include path locations with -I attributes.
Its generally considered bad practice to use relative and absolute paths in the #include statements. Module paths are ok #include <sys/time.h>, where sys could be considered the module. Include the file with just its name and possibly the module, then handle the location with the compiler options.