refcountedstring/String.h

#pragma once
#include <iostream>
#include <cstring>
#include <memory>
#include "StringValue.h"
#include "Char.h"
class Char;



/* Design decisions:
 *              - Everything related to ref-counting is the responsibility of the StringValue class
 *              - Anything dynamically allocated is owned (and thus once deleted) by the StringValue class
 *                (including itself -- this is possible because of the reference counting mechanism) */
class String
{
private:

    StringValue* _str;

    char* copy_and_concat(const String& str) const;
    char* copy_and_concat(char c) const;

public:

    String() noexcept;
    String(const char*);
    String(const String&) noexcept;
    String& operator=(String);
    String(String&&) noexcept;
    ~String() noexcept;

    friend void swap(String&, String&) noexcept;
    String operator+(const String&) const;
    String& operator+=(const String&);
    String operator+(char) const;
    String& operator+=(char);
    bool operator==(const String&) const;
    const char& operator[](size_t) const;
    Char operator[](size_t);

    size_t size() const noexcept;    // does not include null-terminator
    const char* c_str() const;

    friend std::istream& operator>>(std::istream&, String&);
    friend class Char;
};

std::ostream& operator<<(std::ostream&, const String&);