C++ - Zed

# C++

C++ support is available natively in Zed.

- Tree-sitter: tree-sitter/tree-sitter-cpp
- Language Server: clangd/clangd

## Binary

You can configure which `clangd` binary Zed should use.

To use a binary in a custom location, add the following to your `settings.json`:

    {
      "lsp": {
        "clangd": {
          "binary": {
            "path": "/path/to/clangd",
            "arguments": []
          }
        }
      }
    }

If you want to disable Zed looking for a `clangd` binary, you can set `ignore_system_version` to `true`:

    {
      "lsp": {
        "clangd": {
          "binary": {
            "ignore_system_version": true
          }
        }
      }
    }

## Arguments

You can pass any number of arguments to clangd. To see a full set of available options, run `clangd --help` from the command line. For example with `--function-arg-placeholders=0` completions contain only parentheses for function calls, while the default (`--function-arg-placeholders=1`) completions also contain placeholders for method parameters.

    {
      "lsp": {
        "clangd": {
          "binary": {
            "path": "/path/to/clangd",
            "arguments": ["--function-arg-placeholders=0"]
          }
        }
      }
    }

## Formatting

By default Zed will use the `clangd` language server for formatting C++ code. The Clangd is the same as the `clang-format` CLI tool. To configure this you can add a `.clang-format` file. For example:

    ---
    BasedOnStyle: LLVM
    IndentWidth: 4
    ---
    Language: Cpp
    # Force pointers to the type for C++.
    DerivePointerAlignment: false
    PointerAlignment: Left
    ---

See Clang-Format Style Options for a complete list of options.

You can trigger formatting via {#kb editor::Format} or the `editor: format` action from the command palette or by adding `format_on_save` to your Zed settings:

      "languages": {
        "C++": {
          "format_on_save": "on",
          "tab_size": 2
        }
      }

## More server configuration

In the root of your project, it is generally common to create a `.clangd` file to set extra configuration.

    CompileFlags:
      Add:
        - "--include-directory=/path/to/include"
    Diagnostics:
      MissingIncludes: Strict
      UnusedIncludes: Strict

For more advanced usage of clangd configuration file, take a look into their official page.

## Compile Commands

For some projects Clangd requires a `compile_commands.json` file to properly analyze your project. This file contains the compilation database that tells clangd how your project should be built.

### CMake Compile Commands

With CMake, you can generate `compile_commands.json` automatically by adding the following line to your `CMakeLists.txt`:

    set(CMAKE_EXPORT_COMPILE_COMMANDS ON)

After building your project, CMake will generate the `compile_commands.json` file in the build directory and clangd will automatically pick it up.