error "OpenCV 4.x+ requires enabled C++11 support"

[Ajaygirish1]

Hey all,
I am facing the below error,
error "OpenCV 4.x+ requires enabled C++11 support" while executing catkin make,
I have tried inserting
set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_STANDARD_REQUIRED TRUE)
in Cmake.txt of darknet_ros node but still doesnt work.

CMakeLists.txt

[cardboardcode]

You can try have a look at pull request #202 by @kunaltyagi.

Compiled the version under this fork and it solved the compilation issue.

Hope this helps.

[mywnajsldkf]

which openCV version do you use??

[kunaltyagi]

I use OpenCV@HEAD

[mywnajsldkf]

@kunaltyagi oh! thank you for answering. I installed opencv3.4.6, after catkin_make darknet_ros, I met error "OpenCV 4.x+ requires enabled C++11 support" can I you your solution(256ea50 by following this commit) to solve my problem??

[mywnajsldkf]

I want to use darknet_ros to detect something!!

[kunaltyagi]

I installed opencv3.4.6, after catkin_make darknet_ros, I met error "OpenCV 4.x+ requires enabled C++11 support" can I you your solution(256ea50 by following this commit) to solve my problem??

You have OpenCV 4 not 3 installed, and yes, my fork works with latest OpenCV and ROS. If you want to work on darknet directly, I'd recommend https://github.com/alexeyab/darknet instead.

[mywnajsldkf]

I installed opencv3.4.6, after catkin_make darknet_ros, I met error "OpenCV 4.x+ requires enabled C++11 support" can I you your solution(256ea50 by following this commit) to solve my problem??

You have OpenCV 4 not 3 installed, and yes, my fork works with latest OpenCV and ROS. If you want to work on darknet directly, I'd recommend https://github.com/alexeyab/darknet instead.

Oh, I'm sorry for bothering you
But when I enter pkg_config --modeversion opencv opencv3.4.6 show up. also I tested it on python. And I want to detect on ROS.

[prit-ubuntu]

@Ajaygirish1 and @mywnajsldkf did you end up finding a solution? I am facing the same problems. I'm using Ubuntu 18.04 and OpenCV 3.4.0 for this purpose.

[mywnajsldkf]

@prit-ubuntu Do you want to use OpenCV 3.4.0 for using darknet_ros? If you want it, I recommend following this procedure

1. Delete OpenCV already installed your hardware!
   sudo find / -name "*opencv*" -exec rm -i {} \;
2. Install OpenCV (https://jkjung-avt.github.io/opencv-on-nano/)
   i recommend this blog. And If you use ROS version1, ROS default python package is python2.7. So I changed shell script a little to install OpenCV 3.4.6 on python2

[prit-ubuntu]

@mywnajsldkf so basically the solution you mentioned above worked for you to run darknet_ros? Yes, i do want to use OpenCV 3.4.0 for darknet_ros.

[mywnajsldkf]

@prit-ubuntu It is best for me!
darknet_ros is working on OpenCV 3.4.6 too!

[kunaltyagi]

You can also use my fork (I really should move it to point to AlexyAB's implementation)

[prit-ubuntu]

@mywnajsldkf and @kunaltyagi I'm happy to inform you that I have finally managed to compile darknet_ros on my system! Thanks for your help.

[Silerqin]

hi, I am getting the same issue. Can I know how to solve it? @kunaltyagi I have see your fork, can I know how to install it?