Can I set clangd works only with standard from c++17

[stokhos]

Hi,

Is there a way to set clangd only work with c++ 17 standard? best

[fannheyward]

~Try set "clangd.arguments": ["-std=c++17"] to your coc-settings.json.~

Use "clangd.fallbackFlags": [ "-std=c++17" ].

[stokhos]

How can I do this? Do I need to unninstall coc-clangd? below is my coc-settings.json { "languageserver": { "clangd": { "command": "clangd", "args": ["--background-index", "-std=c++17"], "rootPatterns": ["compile_flags.txt", "compile_commands.json"], "filetypes": ["c", "cpp"] }, } this works, but is there a way of not deleting coc-clangd and add "clangd.arguments": ["-std=c++17"] to your coc-settings.json at same time?

[hokein]

To clarify, the flag -std=c++17 is not passed to the clangd binary argument, it needs to be added in the compilation command. If you use the compile_flags.txt, just put it there.

is there a way of not deleting coc-clangd and add "clangd.arguments": ["-std=c++17"] to your coc-settings.json at same time?

Yes, if you use coc-clangd, the coc-settings.json is like below (not other fields)

{
   "clangd.arguments": [...]
}

[stokhos]

It works. Thanks guys!

[treeshateorcs]

i did as you said in the second comment in this thread and i now get

[coc.nvim] The "clangd" server crashed 5 times in the last 3 minutes. The server will not be restarted.

P.S. putting it into compile_flags.txt works tho, but i would rather not do that every time i start a new project

[kadircet]

that's WAI, as indicated in Haojian's comment

To clarify, the flag -std=c++17 is not passed to the clangd binary argument, it needs to be added in the compilation command. If you use the compile_flags.txt, just put it there.

if you pass it to clangd, command line parsing will fail and clangd will exit with a non-zero error code.

[Waqar144]

Yes, if you use coc-clangd, the coc-settings.json is like below (not other fields)

{
   "clangd.arguments": [...]
}

Doing this make clangd crash very quickly. Not recommended anymore.

I can't get C++17 support, so many errors. It isn't able to find string_view even. Can anyone suggest something else?

[sam-mccall]

Doing this make clangd crash very quickly

Well, are you putting clangd flags in there? -std=c++17 is not a clangd flag, it must go in your compile_commands.json or compile_flags.txt instead. (clangd will not crash in this case, but it won't start correctly either).

Incidentally, if you really want to set this globally for all projects, the next release (clangd 11) will make this possible.

[mixolydianmel]

I used the clangd.fallbackFlags option and it worked fine for me. This is my coc-settings.json:

{
    "clangd.fallbackFlags": [ "-std=c++17" ]
}

[Waqar144]

I have found the compile_flags.txt method to be the best. However I still have the problem where clangd thinks .h files are C header files so it keeps complaining

[kadircet]

you can also put -xc++-header into your compile_flags.txt

[zhiwayzhang]

I used the clangd.fallbackFlags option and it worked fine for me. This is my coc-settings.json:

{
    "clangd.fallbackFlags": [ "-std=c++17" ]
}

It's works! It's take me hole day to setting this config, every solution from internet didn't work.😭

[lijh8]

I used the clangd.fallbackFlags option and it worked fine for me. This is my coc-settings.json:

{
    "clangd.fallbackFlags": [ "-std=c++17" ]
}

I'm trying C++ in VSCode with clangd. I need this:

    "clangd.fallbackFlags": [
        "-std=c++2a",
    ],

to turn off the error messages in problem pane in VSCode, e.g.:

No member named 'exchange' in namespace 'std'

It has to be in "clangd.fallbackFlags". If I put it in "clangd.arguments", the outline view does not work.

[MuhammadSawalhy]

I opened the output of coc-clangd to see why this solution is not working for me and this is what I got:

:CocCommand workspace.showOutput clangd

clangd: Unknown command line argument '-std=c++17'.  Try: '/usr/bin/clangd --help'
clangd: Did you mean '--j=c++17'?

[fannheyward]

@MuhammadSawalhy what's your clangd version?

[MuhammadSawalhy]

@MuhammadSawalhy what's your clangd version?

I switched to clangd.fallbackFlags instead of clangd.arguments and it works now. Thanks!

[MuhammadSawalhy]

This doesn't work with C files! How to use clangd.fallbackFlags with cpp files only?

[Waqar144]

Read the following link carefully, then use compile commands to solve your problems.

https://clangd.llvm.org/installation.html

[lijh8]

// workspace settings: //.vscode/settings.json "clangd.fallbackFlags": [ //"-std=c99", "-I../foo", ],

for C files, I comment the -std option

[MuhammadSawalhy]

// workspace settings:

I am coding separate and independent C++ and C files in the same project. This is my repo which contains solutions for problems from sites like LeetCode, Hackerrank, and Codeforces.

So I need a way to configure -std flag differently for C++ and C files.

[Leskodamus]

// workspace settings:

I am coding separate and independent C++ and C files in the same project. This is my repo which contains solutions for problems from sites like LeetCode, Hackerrank, and Codeforces.

So I need a way to configure -std flag differently for C++ and C files.

@MuhammadSawalhy Have you found a solution for having the -std flag separately for C and C++ files?

[colourfulspring]

"clangd.fallbackFlags": [ "-std=c++17" ]

It works! Thanks for your reply!