Visual Studio: 2022/2026 | License: MIT | Version: 1.0.0

View on GitHub: https://github.com/Ghost-Girls/InlayIndex

InlayIndex is a Visual Studio 2022/2026 extension that enhances C/C++ code readability by providing inline hints for array indices, enum values, and struct field names directly within the editor.

Powered by ClangSharp (libclang) for precise AST-level code parsing, it brings a code-reading experience comparable to CLion's inlay hints to Visual Studio.

Features

Array Index Hints

Display [0]:, [1]:, [N]: labels for each element in array initializers, supporting up to 10 dimensions.

// Before: hard to tell which element is which
int matrix[2][3] = { 1, 2, 3, 4, 5, 6 };

// After: indices are displayed inline
int matrix[2][3] = { [0][0]:1, [0][1]:2, [0][2]:3, [1][0]:4, [1][1]:5, [1][2]:6 };

Dimension	Display
1D	`[0]:` `[1]:` `[2]:`
2D	`[0][0]:` `[0][1]:` `[1][0]:`
3D	`[0][0][0]:` `[0][0][1]:` `[0][1][0]:`
4D	`[0][0][0][0]:` `[0][0][0][1]:`
5D+	and so on, up to 10 dimensions

Struct Array Hints

struct Point { int x; int y; };
struct Point pts[3] = {
    [0]:{ .x:1, .y:2 },
    [1]:{ .x:3, .y:4 },
    [2]:{ .x:5, .y:6 }
};

Enum Value Hints

Display NAME=value labels at enum definitions, showing both explicitly assigned and automatically computed values.

// Before: need to manually count
enum Color { RED, GREEN, BLUE };

// After: values are displayed inline
enum Color { RED=0, GREEN=1, BLUE=2 };

Struct Field Hints

Display .fieldName: labels within struct/unions initializers, recursively for nested structures.

struct Point { int x; int y; };
struct Point points[2] = {
    [0]:{ .x:1, .y:2 },
    [1]:{ .x:3, .y:4 }
};

Depth-based Color Coding

Array indices are color-coded by nesting depth using a rainbow scheme, making multi-dimensional structures visually distinguishable.

Depth	Color
0	Red
1	Orange
2	Yellow
3	Green
4+	Cyan, Blue, Purple (cycling)

Installation

Via VSIX (Manual)

Download the latest .vsix from the Releases page on GitHub
Double-click the .vsix file
Follow the installation wizard
Restart Visual Studio

Build from Source

git clone https://github.com/Ghost-Girls/InlayIndex.git
cd InlayIndex

Open InlayIndex.slnx in Visual Studio, then build and deploy:

Release: Build the InlayIndex project → produces .vsix in bin/Release/
Debug: Set InlayIndex as startup project → F5 launches Experimental Instance

Configuration

Navigate to Tools → Options → InlayIndex to customize:

Feature Toggles

Option	Default	Description
Array Index Hints	On	Show `[N]:` labels for array elements
Enum Value Hints	On	Show `NAME=value` at enum definitions
Struct Field Hints	On	Show `.fieldName:` in struct initializers

Style

Option	Default	Description
Theme	Orange	Orange / Blue / Green / High Contrast
Font Size	11pt	Range: 5-12pt
Font Weight	Bold	Normal / Medium / SemiBold / Bold
Background Opacity	80%	Range: 0-100%
Depth Colors	On	Rainbow color by nesting depth
Auto Background Color	Off	Auto-generate dark background from foreground (HSL brightness to 12%)
Custom Background Color	#101020	Manual label background (used when Auto Background is off)

Display Limits

Option	Default	Description
Max Dimensions	10	Maximum array dimensions to annotate (1-10)
Max Elements	10000	Maximum elements per array

Project Awareness

Option	Default	Description
VisualGDB Detection	On	Auto-detect include paths from VisualGDB projects
vcxproj Detection	On	Auto-detect include paths from standard vcxproj
CMake Detection	Off	Auto-detect includes from CMake projects

Performance

Option	Default	Description
Debounce Delay	200ms	Delay after editing before re-parsing (100-2000ms)

Architecture

         Source Code
              │
              ▼
  ┌──────────────────────┐
  │    ClangParser       │  ◄── ClangSharp (libclang) AST
  │  (CXTranslationUnit) │
  └──────────┬───────────┘
             │
             ▼
  ┌──────────────────────┐
  │  InlayHintGenerator  │  ◄── Extract: ArrayInfo, EnumInfo, StructInfo
  └──────────┬───────────┘
             │
             ▼
  ┌──────────────────────┐
  │   InlayHintManager   │  ◄── Cache & manage List<InlayHintTag>
  └──────────┬───────────┘
             │ TagsUpdated event
             ▼
  ┌──────────────────────┐
  │  InlayHintTagger     │  ◄── ITagger<IntraTextAdornmentTag>
  │  (GetTags)           │       Create WPF adornments
  └──────────┬───────────┘
             │
             ▼
  ┌──────────────────────┐
  │  Visual Studio       │
  │  Editor Pipeline     │  ◄── Render inline in text view
  └──────────────────────┘

Key Components

Component	File	Responsibility
ClangParser	`Parser/ClangParser.cs`	Parse C/C++ code via ClangSharp AST; dual-mode parsing (unsaved file + temp file fallback)
InlayHintGenerator	`Parser/InlayHintGenerator.cs`	Convert AST results into `InlayHintTag` list with style properties
InlayHintManager	`Adornment/InlayHintManager.cs`	Thread-safe tag cache with `TagsUpdated` event
InlayHintTagger	`Adornment/InlayHintTagger.cs`	`ITagger<IntraTextAdornmentTag>` implementation; creates WPF UI elements
InlayIndexViewCreationListener	`Adornment/InlayIndexViewCreationListener.cs`	View lifecycle; text change debouncing (500ms); retriggers parsing
VisualGDBConfigDetector	`Parser/VisualGDBConfigDetector.cs`	Auto-detect include paths from VisualGDB/vcxproj/CMake
InlayIndexOptionsPage	`Options/InlayIndexOptionsPage.cs`	VS Options dialog integration

Documentation & Support

For full documentation, source code, and to report issues, visit the GitHub repository: https://github.com/Ghost-Girls/InlayIndex

License

MIT License

Publisher: Ghost-Girls

Made for C/C++ developers who value code readability.

InlayIndex