cpp-func-impl.el

C++ class methods implementation timesaver.

• Overview
• Demo
• Features
• Requirements
• Installation
• Usage
• Customizations
• cpp-func-impl-comment-string
• Limitations
• License
• Contributing

Overview

This Emacs package provides a utility to generate out-of-line method implementations for C++ classes. It leverages Tree Sitter for accurate parsing of C++ declarations directly from header files.

Place your cursor on a C++ method declaration inside a header file, run the command, and the function body will be automatically generated and inserted in the corresponding source (.cpp) file.

Templated methods are fully supported.

Version: 0.1.2

Caution

I am new to Emacs Lisp and this plugin is still in early stages and it might not work all the time. Please open an issue if there are any problems.

Demo

1. Implement function at point

• Regular functions

• Templated functions

2. Implement all methods from a class

3. Implement selected methods from a class

4. Implement methods from highlighted region

5. Create concrete class from another class

Features

• Implement all the methods in a class
• Implement function at point
• Implement selected function(s)
• Implement methods from highlighted region
• Implement concrete class from a given class
• Skip header-only method declarations from implementation (only in implement all methods command):
  • inline
  • constexpr
  • consteval
  • constinit
• Skip delete and default methods (only in implement all methods command)

Note

Concrete class are ordinary classes that can be instantiated and have no virtual functions.

Requirements

• Emacs 29+ with Tree-sitter support.
• C++ major mode using Tree-sitter backend (`c++-ts-mode`).
• A valid project structure with corresponding `.cpp` files discoverable via `ff-find-other-file`.

Installation

Use VC with use-package

(use-package cpp-func-impl
    :vc (cpp-func-impl :url "https://github.com/dheerajshenoy/cpp-func-impl")
    :commands
    (cpp-func-impl-implement
    cpp-func-impl-implement-all
    cpp-func-impl-implement-selected
    cpp-func-impl-implement-region
    cpp-func-impl-implement-dwim
    cpp-func-impl-concrete-class)
    :custom
    (cpp-func-impl-comment-string "// TODO: `%m` `%d` `%t` `%c`"))

or clone the repo and load it manually

(use-package cpp-func-impl
    :load-path "<path-to-cloned-directory>"
    :commands
    (cpp-func-impl-implement
    cpp-func-impl-implement-all
    cpp-func-impl-implement-selected
    cpp-func-impl-implement-region
    cpp-func-impl-implement-dwim
    cpp-func-impl-concrete-class)
    :custom
    (cpp-func-impl-comment-string "// TODO: `%m` `%d` `%t` `%c`"))

Commands

You have the following commands that can be invoked:

• cpp-func-impl-implement - Implements the method at point.

• cpp-func-impl-implement-selected - Implements selected methods from a class.

• cpp-func-impl-implement-all - Implements all the method inside the class (assuming the point is inside the class).

• cpp-func-impl-implement-region - Implements all methods inside the region.

  [!NOTE] when using cpp-func-impl-implement-region make sure that the highlighted region contains methods from one class/struct only. Otherwise it may lead to unexpected function implementations.

• cpp-func-impl-implement-dwim - Implements methods in a DWIM (do what I mean) fashion.

  If there is active highlight region, then implement methods from the highlighted region, else implement the method at point.

• cpp-func-impl-concrete-class - Creats a concrete class of the class where the point lies inside.

If you call the commands with a prefix argument a comment is inserted. This comment can be changed by setting the variable cpp-func-impl-comment-string.

Customizations

You can customize the comment inserted into the implementation body by setting the variable cpp-func-impl-comment-string.

cpp-func-impl-comment-string

The comment string can include valid format specifiers mentioned below which get injected with information like method-name, class-name, time, date.

Following format specifiers are supported:

Format Specifier	Meaning
%c	Class Name
%m	Method Name
%t	Current Time
%d	Current Date

Example:

  (setopt cpp-func-impl-comment-string "// TODO: Implement `%m` for the class `%c. Added at `%t` on `%d`")

Limitations

• Does not support auto-discovery of already existing method definition.

Changelog

Check CHANGELOG.md

TODO

• Trim default arguments
• Nested class environments
• Auto discovery of already existing method definition.
• Type qualifier awareness
• Virtual qualifier awareness
• disable implementing header-only methods
• disable implementing default and delete methods
• Complex class
• Region highlight implement

License

MIT License

Contributing

Contributions, suggestions, or bug reports are welcome. Feel free to fork and submit a pull request or open an issue.