'nlohmann/json.hpp' file not found

[Honorable22]

For some reason I am getting this error message on basic setup when running this library on VS Code:

UIDeveloperTest.cpp:26:10: fatal error: 'nlohmann/json.hpp' file not found
#include "nlohmann/json.hpp"
^~~~~~~~~~~~~~~~~~~
1 error generated.

I can not seem to find the solution to this error.

[nlohmann]

In order to asses your issue, we need the following information:

• What is the issue you have?

• Please describe the steps to reproduce the issue. Can you provide a small but working code example?

• What is the expected behavior?

• And what is the actual behavior instead?

• Which compiler and operating system are you using? Is it a supported compiler?

• Did you use a released version of the library or the version from the develop branch?

• If you experience a compilation error: can you compile and run the unit tests?

[Honorable22]

When trying to include the library with the following line:

#include <iostream>
#include <fstream>
#include <cmath>

#include "nlohmann/json.hpp"

using json = nlohmann::json;

using namespace std;

int main() {
  cout << "Hello World!";
  return 0;
}

I get this error after I compile it:
fatal error: 'nlohmann/json.hpp' file not found

I am running Visual Studio Code on a Mac I believe its being compiled using clang

[nlohmann]

Where did you put the json.hpp file?

[Honorable22]

Inside of a folder labeled nlohmann and then that is inside of a folder labeled include.

[nlohmann]

I am not familiar with Visual Studio Code. Maybe change the include to #include <nlohmann/json.hpp> and try to set the include path to your project path.

[Honorable22]

Yes I tried to change include to <nlohmann/json.hpp>, it didn't make a difference.

[nlohmann]

What’s the include path? Which build system are you using?

[Honorable22]

"includePath": [
"${workspaceFolder}/**"
],

using clang++ as the build system

[nlohmann]

I'm sorry, I have no idea how to fix this error as it is not related to this library. Please seek help in a forum for VS Code.

[shivam-51]

@Honorable22 Did you get any solution?

[Honorable22]

No. I did not get an solution.

…

On Sep 29, 2020, at 8:46 AM, shivam kumar singh ***@***.***> wrote:  @Honorable22 Did you get any solution? — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub, or unsubscribe.

[shivam-51]

Never mind, My code compiles now :)

[Honorable22]

What was your solution?

…

On Sep 29, 2020, at 8:58 AM, shivam kumar singh ***@***.***> wrote:  Never mind, My code compiles now :) — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub, or unsubscribe.

[shivam-51]

What was your solution?

First I had to install the nlohmann_json package from apt sudo apt install nlohmann-json-dev
then simply g++ file.cpp

[Honorable22]

Thank you for sharing.

…

On Sep 29, 2020, at 10:53 AM, shivam kumar singh ***@***.***> wrote:  What was your solution? First I had to install the nlohmann_json package from apt sudo apt install nlohmann-json-dev then simply g++ file.cpp — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub, or unsubscribe.

[kevinmukuna]

if you experience the same issue. you can solve it by adding (nlohmann-json) the path to c_cpp_properties.json like this

{
    "configurations": [
        {
            "name": "Mac",
            "includePath": [
                "${workspaceFolder}/**",
                "/opt/homebrew/Cellar/nlohmann-json/3.10.5/include/"
            ],
           ...
          ...

c_cpp_properties.json can be found in your current working dir under .vscode dir

[maxpain]

@kevinmukuna didn't help :(

[anu-n87]

I tried installing nlohmann json and some files found missing in /usr/include/nlohmann. I used sudo apt-get install nlohmann-json3-dev for installation and it was success. However some files are missing which I use in my code and hence the code is having compilation issues. I tried copying those files from other system. But it did not work :( My system details:
Distributor ID: Ubuntu
Description: Ubuntu 20.04.5 LTS
Release: 20.04
Codename: focal
Architecture is arm64.
Can anyone please help to get it resolved?

@nlohmann : Could you please help on this?

[nlohmann]

I am not maintaining this package. Please contact the maintainer.

[anu-n87]

I am not maintaining this package. Please contact the maintainer.

@nlohmann Thanks for the reply. Can I please know the details of the maintainer?

[nlohmann]

I do not know. You should be able to look this up in your distro.

[vidyulshah]

When I do sudo apt install nlohmann-json-dev
It give me this:
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package nlohmann-json-dev is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
Any other solution or stable branch available?

[aseem-heg]

sudo apt install libstdc++-12-dev this also did not resolve this error.
still getting error

.plugin_symlinks/flutter_secure_storage_linux/linux/include/json.hpp:18:8: error: macro name missing
/home/aseem/code/pangea_flutter/linux/flutter/ephemeral/.plugin_symlinks/flutter_secure_storage_linux/linux/include/Secret.hpp:12:17: error: implicit instantiation of undefined template 'std::basic_string<char>'
/home/aseem/code/pangea_flutter/linux/flutter/ephemeral/.plugin_symlinks/flutter_secure_storage_linux/linux/include/Secret.hpp:57:25: error: use of undeclared identifier 'nlohmann'