🚀 Strix — A Zero-Dependency Lightweight String Library in C++

A fully self-written, low-level custom string class built from scratch without any standard library string utilities.

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📜 About the Project

Strix is a custom-built string class in C++ designed for:

• Practicing low-level memory management.
• Understanding Rule of Five (copy/move constructors, assignment operators).
• Implementing string operations manually without std::string or <string.h>.

✅ Zero-dependency (no standard string functions).

✅ Deep dive into raw memory, OOP, and exception safety.

✅ Built for performance and learning core C++ internals.

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💡 Features Implemented

Feature	Description
Constructors	Default, C-string (const char*), Copy, Move, and Pre-sized.
Destructor	Safely releases allocated memory.
Rule of 5	Full copy/move assignment and constructor support.
Size & Access	size(), c_str(), mutable and const indexing (operator[]).
Equality & Inequality	== and != operators with efficient comparison.
Relational Operators	<, >, <=, >= — all correctly using lexicographic comparison.
Concatenation	operator+ and operator+= for string joining.
Substring Extraction	substr(start, length) extracts part of the string.
Insert & Erase	Insert substring anywhere; erase part of the string.
Replace	Replace part of the string with another string.
Clear	Reset string to empty.
Iterators (Custom)	Supports begin() and end() to enable range-based loops (for(auto c : str)).

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🔧 How to Use

Example Usage (main.cpp)

#include <iostream>
#include "Strix.h"

int main() {
    Strix s1("Hello");
    Strix s2 = s1;  // Copy constructor
    Strix s3 = Strix("World");  // Move constructor

    std::cout << s1.c_str() << " (size: " << s1.size() << ")\n";

    s2[0] = 'Y';  // Indexing write
    std::cout << s2.c_str() << "\n";

    Strix s4 = s1 + s3;  // Concatenation
    std::cout << s4.c_str() << "\n";

    Strix sub = s4.substr(1, 4);
    std::cout << "Substring: " << sub.c_str() << "\n";

    s4.insert(5, Strix("INSERT"));
    std::cout << "After Insert: " << s4.c_str() << "\n";

    s4.erase(2, 3);
    std::cout << "After Erase: " << s4.c_str() << "\n";

    s4.replace(2, 2, Strix("XX"));
    std::cout << "After Replace: " << s4.c_str() << "\n";

    // Relational comparisons
    if (s1 < s3) std::cout << s1.c_str() << " < " << s3.c_str() << "\n";

    // Range-based loop using iterators
    for (auto ch : s1) {
        std::cout << ch << ' ';
    }
    std::cout << "\n";

    return 0;
}

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🏗 Project Structure

Strix/
├── Strix.h        # Class Declaration (Public & Private APIs)
├── Strix.cpp      # Class Implementation
└── main.cpp       # Test Script

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📚 Key Concepts Demonstrated

1. Raw Memory Management → Manual new[] and delete[] without STL help.
2. Rule of Five → Deep understanding of when and how to write:
   • Copy constructor
   • Move constructor
   • Copy assignment operator
   • Move assignment operator
   • Destructor
3. Operator Overloading → Building intuitive operator-based interfaces (+, ==, !=, etc.).
4. Iterators → Enable seamless use with for(auto c : str).

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🚀 How to Compile & Run

g++ -std=c++17 main.cpp Strix.cpp -o strix
./strix

✅ No external dependencies required.

✅ Pure C++.

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📈 Future Ideas / Improvements

• Implement memory optimizations like Small String Optimization (SSO).
• Add find and replace_all methods.
• Make it thread-safe (with optional mutexes).
• Add Unicode/UTF-8 support.