.. _program_listing_file_cif++_row.hpp:

Program Listing for File row.hpp
================================

|exhale_lsh| :ref:`Return to documentation for file <file_cif++_row.hpp>` (``cif++/row.hpp``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   /*-
    * SPDX-License-Identifier: BSD-2-Clause
    *
    * Copyright (c) 2022 NKI/AVL, Netherlands Cancer Institute
    *
    * Redistribution and use in source and binary forms, with or without
    * modification, are permitted provided that the following conditions are met:
    *
    * 1. Redistributions of source code must retain the above copyright notice, this
    *    list of conditions and the following disclaimer
    * 2. Redistributions in binary form must reproduce the above copyright notice,
    *    this list of conditions and the following disclaimer in the documentation
    *    and/or other materials provided with the distribution.
    *
    * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
    * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
    * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
    * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
    * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
    * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
    * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
    * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
    * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    */
   
   #pragma once
   
   #include "cif++/item.hpp"
   
   #include <array>
   
   namespace cif
   {
   
   namespace detail
   {
   
       // some helper classes to help create tuple result types
       template <typename... C>
       struct get_row_result
       {
           static constexpr std::size_t N = sizeof...(C);
   
           get_row_result(const row_handle &r, std::array<uint16_t, N> &&items)
               : m_row(r)
               , m_items(std::move(items))
           {
           }
   
           const item_handle operator[](uint16_t ix) const
           {
               return m_row[m_items[ix]];
           }
   
           template <typename... Ts, std::enable_if_t<N == sizeof...(Ts), int> = 0>
           operator std::tuple<Ts...>() const
           {
               return get<Ts...>(std::index_sequence_for<Ts...>{});
           }
   
           template <typename... Ts, std::size_t... Is>
           std::tuple<Ts...> get(std::index_sequence<Is...>) const
           {
               return std::tuple<Ts...>{ m_row[m_items[Is]].template as<Ts>()... };
           }
   
           const row_handle &m_row;
           std::array<uint16_t, N> m_items;
       };
   
       // we want to be able to tie some variables to a get_row_result, for this we use tiewraps
       template <typename... Ts>
       struct tie_wrap
       {
           tie_wrap(Ts... args)
               : m_value(args...)
           {
           }
   
           template <typename RR>
           void operator=(const RR &&rr)
           {
               // get_row_result will do the conversion, but only if the types
               // are compatible. That means the number of parameters to the get()
               // of the row should be equal to the number of items in the tuple
               // you are trying to tie.
   
               using RType = std::tuple<typename std::remove_reference<Ts>::type...>;
   
               m_value = static_cast<RType>(rr);
           }
   
           std::tuple<Ts...> m_value;
       };
   
   } // namespace detail
   
   template <typename... Ts>
   auto tie(Ts &...v)
   {
       return detail::tie_wrap<Ts &...>(std::forward<Ts &>(v)...);
   }
   
   // --------------------------------------------------------------------
   
   class row : public std::vector<item_value>
   {
     public:
       row() = default;
   
       item_value* get(uint16_t ix)
       {
           return ix < size() ? &data()[ix] : nullptr;
       }
   
       const item_value* get(uint16_t ix) const
       {
           return ix < size() ? &data()[ix] : nullptr;
       }
   
     private:
       friend class category;
       friend class category_index;
   
       template <typename, typename...>
       friend class iterator_impl;
   
       void append(uint16_t ix, item_value &&iv)
       {
           if (ix >= size())
               resize(ix + 1);
           
           at(ix) = std::move(iv);
       }
   
       void remove(uint16_t ix)
       {
           if (ix < size())
               at(ix) = item_value{};
       }
   
       row *m_next = nullptr;
   };
   
   // --------------------------------------------------------------------
   
   class row_handle
   {
     public:
       friend struct item_handle;
       friend class category;
       friend class category_index;
       friend class row_initializer;
       template <typename, typename...> friend class iterator_impl;
   
       row_handle() = default;
   
       row_handle(const row_handle &) = default;
       row_handle(row_handle &&) = default;
   
       row_handle &operator=(const row_handle &) = default;
       row_handle &operator=(row_handle &&) = default;
   
       row_handle(const category &cat, const row &r)
           : m_category(const_cast<category *>(&cat))
           , m_row(const_cast<row *>(&r))
       {
       }
   
       const category &get_category() const
       {
           return *m_category;
       }
   
       bool empty() const
       {
           return m_category == nullptr or m_row == nullptr;
       }
   
       explicit operator bool() const
       {
           return not empty();
       }
   
       item_handle operator[](uint16_t item_ix)
       {
           return empty() ? item_handle::s_null_item : item_handle(item_ix, *this);
       }
   
       const item_handle operator[](uint16_t item_ix) const
       {
           return empty() ? item_handle::s_null_item : item_handle(item_ix, const_cast<row_handle &>(*this));
       }
   
       item_handle operator[](std::string_view item_name)
       {
           return empty() ? item_handle::s_null_item : item_handle(add_item(item_name), *this);
       }
   
       const item_handle operator[](std::string_view item_name) const
       {
           return empty() ? item_handle::s_null_item : item_handle(get_item_ix(item_name), const_cast<row_handle &>(*this));
       }
   
       template <typename... C>
       auto get(C... items) const
       {
           return detail::get_row_result<C...>(*this, { get_item_ix(items)... });
       }
   
       template <typename... Ts, typename... C, std::enable_if_t<sizeof...(Ts) == sizeof...(C) and sizeof...(C) != 1, int> = 0>
       std::tuple<Ts...> get(C... items) const
       {
           return detail::get_row_result<Ts...>(*this, { get_item_ix(items)... });
       }
   
       template <typename T>
       T get(const char *item) const
       {
           return operator[](get_item_ix(item)).template as<T>();
       }
   
       template <typename T>
       T get(std::string_view item) const
       {
           return operator[](get_item_ix(item)).template as<T>();
       }
   
       void assign(const std::vector<item> &values)
       {
           for (auto &value : values)
               assign(value, true);
       }
   
       void assign(std::string_view name, std::string_view value, bool updateLinked, bool validate = true)
       {
           assign(add_item(name), value, updateLinked, validate);
       }
   
       void assign(uint16_t item, std::string_view value, bool updateLinked, bool validate = true);
   
       bool operator==(const row_handle &rhs) const { return m_category == rhs.m_category and m_row == rhs.m_row; }
   
       bool operator!=(const row_handle &rhs) const { return m_category != rhs.m_category or m_row != rhs.m_row; }
   
     private:
       uint16_t get_item_ix(std::string_view name) const;
       std::string_view get_item_name(uint16_t ix) const;
   
       uint16_t add_item(std::string_view name);
   
       row *get_row()
       {
           return m_row;
       }
   
       const row *get_row() const
       {
           return m_row;
       }
   
       void assign(const item &i, bool updateLinked)
       {
           assign(i.name(), i.value(), updateLinked);
       }
   
       void swap(uint16_t item, row_handle &r);
   
       category *m_category = nullptr;
       row *m_row = nullptr;
   };
   
   // --------------------------------------------------------------------
   
   class row_initializer : public std::vector<item>
   {
     public:
       friend class category;
   
       row_initializer() = default;
       row_initializer(const row_initializer &) = default;
       row_initializer(row_initializer &&) = default;
       row_initializer &operator=(const row_initializer &) = default;
       row_initializer &operator=(row_initializer &&) = default;
   
       row_initializer(std::initializer_list<item> items)
           : std::vector<item>(items)
       {
       }
   
       template <typename ItemIter, std::enable_if_t<std::is_same_v<typename ItemIter::value_type, item>, int> = 0>
       row_initializer(ItemIter b, ItemIter e)
           : std::vector<item>(b, e)
       {
       }
   
       row_initializer(row_handle rh);
   
   
       void set_value(std::string_view name, std::string_view value);
   
       void set_value(const item &i)
       {
           set_value(i.name(), i.value());
       }
   
       void set_value_if_empty(std::string_view name, std::string_view value);
   
       void set_value_if_empty(const item &i)
       {
           set_value_if_empty(i.name(), i.value());
       }
   };
   
   } // namespace cif