LibString

A lightweight C++ string utility library designed for embedded or performance-critical applications. LibString provides a minimal subset of std::string functionality with a focus on efficiency, predictable memory usage, and a small code footprint.

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🔧 Purpose & Use Cases

LibString was created to offer a simple replacement for the STL std::string in environments where the standard library is unavailable, too heavy, or where deterministic behavior is required. The class uses a 22‑byte small‑string buffer by default; heap allocations are only introduced when data outgrows that buffer or when UTF‑32 storage is needed. Typical scenarios include:

• Embedded systems with limited RAM/ROM
• Game engines or real-time applications needing fast, inline operations
• Educational projects demonstrating string manipulation internals
• Codebases avoiding dynamic allocations or exceptions

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✅ Features

• Basic string operations: concatenation, comparison, length queries
• Null‑terminated C-style access when needed
• Header‑only implementation (see String.hpp and CharUtils.hpp)
• Unit tests included (StringTest.cpp) to verify correctness

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⚖️ Advantages

1. Small Footprint – no dependency on the full C++ standard library
2. Deterministic behavior for small strings – uses small‑string optimization (SSO) to keep short, pure‑ASCII content entirely on the object itself. Heap allocations only occur when a string grows beyond the SSO buffer or when non‑ASCII (UTF‑32) data is required.
3. Easy to read and extend – source code is intentionally minimal and commented
4. Header-only – drop‑in; just include the headers in your project

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⚠️ Limitations

• Not a drop‑in replacement for all std::string APIs
• Lacks locale/encoding support and advanced algorithms
• Manual bounds checking; users must take care with capacities
• Intended for simple use cases; not optimized for large or complex text processing
• Will allocate on the heap once strings exceed the small‑buffer limit or require UTF‑32 encoding

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📦 Getting Started

1. Copy String.hpp and CharUtils.hpp into your project

2. Include the header where you need string functionality:

   #include "String.hpp"

3. Run the provided test (StringTest.cpp) with your preferred C++ compiler to ensure everything works.

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🧠 Design Notes

The implementation favors clarity over cleverness; functions are implemented with simple loops. A small‑string buffer (22 bytes) lives inside the String object; when only ASCII data fits, everything stays on the stack. The code switches to std::vector‑backed "HEP" modes for larger strings or when decoding UTF‑8, which is where heap allocations occur.

Happy coding! 🚀