Nifty Struct Layout
See the memory layout of C and C++ structs: offsets, sizes, alignment and padding on hover and inline, a fix that reorders fields to save space, and hex, binary and char hovers for numbers.
Maintained. No sign-in. No telemetry. Works in VS Code, Cursor, Windsurf, VSCodium and other editors that use Open VSX.
Features
- Struct layout on hover. Hover over a struct's name to see every field's offset and size, where padding goes and how much, and the total
sizeof and alignment. Unions, typedef'd structs, nested structs, arrays, pointers, bit-fields, #pragma pack and __attribute__((packed)) are all handled.
- Padding shown inline. Wasted bytes appear right in the struct definition (
7B pad), with the struct's size after its closing brace. Switch to all to see every field's offset.
- Make it smaller. When ordering the fields by alignment would save space, the struct name gets a hint and the light bulb offers Reorder fields of Header to save 16 bytes.
- Pick your platform. Sizes and alignment follow the ABI you target: 64-bit Linux/macOS, 64-bit Windows (where
long is 4 bytes), 32-bit x86 or 32-bit ARM.
- Numbers in every base. Hover over a number literal to see it in hex, decimal, binary (grouped by 4 bits) and as a character. Digit separators and suffixes (
1'000'000ULL) work.
- Works on the source text, alongside the C/C++ extension or clangd. Nothing to compile.
- Works in the browser on vscode.dev and github.dev.
Commands
| Command |
What it does |
Nifty Struct Layout: Choose Target ABI… |
Pick the platform to lay structs out for |
Settings
| Setting |
Default |
What it does |
nifty.struct-layout.abi |
auto |
lp64, llp64, ilp32-x86, ilp32-arm, or match this computer |
nifty.struct-layout.inlayHints |
padding |
padding (padding and sizes), all (every field's offset), or off |
nifty.struct-layout.wasteThreshold |
4 |
Suggest reordering when it saves at least this many bytes |
nifty.struct-layout.numberHover |
true |
Show numbers in other bases on hover |
Types from headers the extension can't see (for example a struct defined in another file) are reported as unknown rather than guessed.
Install
- VS Code: search for "Nifty Struct Layout" in the Extensions view, or install from the Visual Studio Marketplace.
- Cursor, Windsurf, VSCodium, Kiro, Antigravity: install from Open VSX.
Privacy
This extension collects no telemetry and needs no account.
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