This is a C++ class definition for a String class. The class provides various functionalities for manipulating and working with strings. Here's a breakdown of the code:

Header:

• Includes necessary header files for ala_exception, allocator, input_iterator, and string_character_traits.
• Defines include guards to prevent multiple inclusions of the header file.

Class definition:

• Template class String with three template parameters:
  • E: The type of characters stored in the string.
  • T: The character traits type for E.
  • A: The allocator type for memory allocation.
• public section: It contains various member functions and type definitions for interacting with the string:
  • Type aliases:
    • value_type: Alias for the type of characters stored in the string.
    • size_type: Alias for the type of size and position values.
    • difference_type: Alias for the type of differences between positions.
    • reference: Alias for a reference to a character in the string.
    • const_reference: Alias for a constant reference to a character in the string.
    • pointer: Alias for a pointer to a character in the string.
    • const_pointer: Alias for a constant pointer to a character in the string.
    • iterator: Alias for an iterator type that iterates over characters in the string.
  • _NPOS_string: Constant value representing "not found" position (npos).
  • Constructors:
    • Default constructor: Initializes an empty string.
    • Constructor with size parameter: Initializes a string with the given size filled with E's default value.
    • Copy constructor: Creates a new string from another string.
    • Constructor with pointer and size parameters: Initializes a string from an existing character array.
    • Constructor with pointer: Initializes a string from an existing null-terminated character array.
    • Constructor with size and value_type parameters: Initializes a string with the given size filled with the specified character.
    • Additional constructors for converting numbers to strings:
      • Converts a signed integer to a string.
      • Converts an unsigned integer to a string.
  • Member functions:
    • data(): Returns a constant pointer to the underlying character array.
    • c_str(): Returns a null-terminated C-style string.
    • capacity(): Returns the capacity of the string (allocated memory).
    • size(): Returns the size of the string (number of characters).
    • max_size(): Returns the maximum size the string can hold.
    • resize(size_type n, value_type c): Changes the size of the string to n and fills the new characters with c.
    • operator=(String<E, T, A>& ref): Assignment operator that copies the contents of another string.
    • operator+=(E c): Appends a character to the string.
    • operator-=(size_type n): Increases the capacity of the string by n.
    • operator+(const String<E, T, A>& ref): Concatenates two strings.
    • substr(size_type pos = 0, size_type len = npos): Returns a substring from the string.
    • operator[](size_type pos): Returns the character at a specific position.
    • erase(size_type pos = 0, size_type len = npos): Erases a substring from the string.
    • replace(size_type pos, size_type len, size_type n, E c): Replaces a substring with a specified character repeated a certain number of times.
    • find(const_pointer s, size_type pos, size_type n): Finds the first occurrence of a substring in the string.
    • find(const String<E, T, A>& str, size_type pos = 0): Finds the first occurrence of another string in the string.
• Private members:
  • str: Pointer to the underlying character array.
  • size_of_str: Size of the string (number of characters).
  • capacity_of_str: Capacity of the string (allocated memory).

Overall, this class provides a comprehensive and efficient implementation for handling strings in C++.

Dependencies

This library has a dependency on the allocator class, which is available in the KHAAdotPK/allocator repository. Ensure that you have the allocator library installed or included in your project before using this string library. You can achieve this by cloning the KHAAdotPK/allocator repository into your project's lib folder/directory.

Example Usage:

/*
 * string/main.cpp
 * Wrintten by Q@khaa.pk
 */
#include <iostream>
#include "src/String.hh"
using namespace::cc_tokenizer;

int main(int argc, char* argv[])
{
    String<char> ss("NLP using Transformers");
    std::cout<< ss.c_str() << std::endl;
    /*
        10 is starting index into the target string
        12 is the size of the target string
        5 is the number of replacements in the target string
        'Q' is the replacing 
     */
    ss.replace(10, 12, 5, 'Q');
    std::cout<< ss.c_str() << std::endl;

    String<char> obj("help");
    String<char> obj1("help");
    std::cout<< obj.compare(obj1) << std::endl;

    obj1.replace(3, 1, 1, '2');
    std::cout<< obj1.c_str() << std::endl;
    std::cout<< obj1.compare(obj) << std::endl;

    String<char> tmm("Transformer model is CNN with memory");
    std::cout<< tmm.size() << std::endl;
    // Find 'C' from index 0 to 22, if found return the index of the vector 'C' from the begining of the string(index 0)
    std::cout<< tmm.rfind('C', 22) << std::endl;

    String<char> N("Transformer model");
  
    String<char> L(" is CNN with");
    String<char> P(" memory.");

    N + L + P; //N = N + L + P;

    std::cout<< N.c_str() << std::endl;

    return 0;
}

License

This project is governed by a license, the details of which can be located in the accompanying file named 'LICENSE.' Please refer to this file for comprehensive information.