classlayout.nvim

See where your bytes go without leaving Neovim.

Visualize C/C++ struct and class memory layouts — field offsets, padding, alignment — in a floating window. Hover over a type or variable and see exactly how the compiler laid it out.

Features

• Works on structs, classes, unions, and STL types
• Resolves variables to their underlying type via clangd
• Auto-detects compiler flags from compile_commands.json
• Cached — first lookup compiles, subsequent lookups are instant

Requirements

• Neovim >= 0.10
• clang in PATH
• clangd for type resolution from variables and qualified types

Install

-- lazy.nvim
{
  "J-Cowsert/classlayout.nvim",
  ft = { "c", "cpp" },
  opts = {},
}

Configuration

Default config — override what you need:

require("classlayout").setup({
  keymap = "<leader>cl",
  compiler = "clang",
  args = {},
  compile_commands = true,
})

Usage

Cursor on a type name or variable. Press <leader>cl or :ClassLayout. Press q to close.

The layout is based on the saved file — save before invoking.