StringRef.h

/*
 * Gamedev Framework (gf)
 * Copyright (C) 2016-2019 Julien Bernard
 *
 * This software is provided 'as-is', without any express or implied
 * warranty.  In no event will the authors be held liable for any damages
 * arising from the use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 *    claim that you wrote the original software. If you use this software
 *    in a product, an acknowledgment in the product documentation would be
 *    appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such, and must not be
 *    misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
 */
#ifndef GF_STRING_REF_H
#define GF_STRING_REF_H

#include <cstring>
#include <string>

namespace gf {
#ifndef DOXYGEN_SHOULD_SKIP_THIS
inline namespace v1 {
#endif

  class StringRef {
  public:
    using iterator = const char*;
    using const_iterator = const char*;

    constexpr StringRef()
    : m_data(nullptr)
    , m_size(0)
    {

    }

    constexpr StringRef(std::nullptr_t)
    : m_data(nullptr)
    , m_size(0)
    {

    }

    constexpr StringRef(const char *str, std::size_t size)
    : m_data(str)
    , m_size(size)
    {

    }

    StringRef(const char *str)
    : m_data(str)
    , m_size(std::char_traits<char>::length(str))
    {

    }

    StringRef(const std::string& str)
    : m_data(str.data())
    , m_size(str.size())
    {

    }

    constexpr StringRef(const char *b, const char *e)
    : m_data(b)
    , m_size(e - b)
    {

    }

    constexpr const char *getData() const noexcept {
      return m_data;
    }

    constexpr std::size_t getSize() const noexcept {
      return m_size;
    }

    constexpr bool isEmpty() const noexcept {
      return m_size == 0;
    }

    constexpr const_iterator begin() const noexcept {
      return m_data;
    }

    constexpr const_iterator end() const noexcept {
      return m_data + m_size;
    }

    constexpr char operator[](std::size_t index) const {
      return m_data[index];
    }

    std::string toString() const {
      if (m_size == 0 || m_data == nullptr) {
        return "";
      }

      return std::string(m_data, m_size);
    }

  private:
    const char *m_data;
    std::size_t m_size;
  };


#ifndef DOXYGEN_SHOULD_SKIP_THIS
}
#endif
}

#endif // GF_STRING_REF_H