concept.hpp

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// -----------------------------------------------------------------------------------------------------
// Copyright (c) 2006-2022, Knut Reinert & Freie Universität Berlin
// Copyright (c) 2016-2022, Knut Reinert & MPI für molekulare Genetik
// This file may be used, modified and/or redistributed under the terms of the 3-clause BSD-License
// shipped with this file and also available at: https://github.com/seqan/seqan3/blob/master/LICENSE.md
// -----------------------------------------------------------------------------------------------------
 
#pragma once
 
#include <concepts>
#include <initializer_list>
#include <iterator>
#include <type_traits>
 
#include <seqan3/core/platform.hpp>
 
#if SEQAN3_WORKAROUND_GCC_NO_CXX11_ABI
#    include <string>
 
namespace seqan3::detail
{
 
template <typename basic_string_t>
struct is_basic_string : std::false_type
{};
 
template <typename value_t, typename traits_t, typename allocator_t>
struct is_basic_string<std::basic_string<value_t, traits_t, allocator_t>> : std::true_type
{};
 
template <typename basic_string_t>
constexpr bool is_basic_string_v = is_basic_string<basic_string_t>::value;
 
} // namespace seqan3::detail
#endif // SEQAN3_WORKAROUND_GCC_NO_CXX11_ABI
 
namespace seqan3
{
 
template <typename type>
concept container = requires (type val, type val2, type const cval, typename type::iterator it) {
                        // member types
                        typename type::value_type;
                        typename type::reference;
                        typename type::const_reference;
                        /*
    typename type::iterator;
    requires std::forward_iterator<typename type::iterator>;
    // NOTE check whether iterator is const convertible
    {it} -> std::same_as<typename type::const_iterator>;
 
    typename type::const_iterator;
    requires std::forward_iterator<typename type::const_iterator>;
 
    typename type::difference_type;
    typename type::size_type;
    requires std::is_same_v<
        typename type::difference_type,
        typename std::iterator_traits<typename type::iterator>::difference_type
    >;
    requires std::is_same_v<
        typename std::iterator_traits<typename type::iterator>::difference_type,
        typename std::iterator_traits<typename type::const_iterator>::difference_type
    >;
*/
                        // methods and operator
                        {
                            type{}
                            } -> std::same_as<type>; // default constructor
                        {
                            type{type{}}
                            } -> std::same_as<type>; // copy/move constructor
                        {
                            val = val2
                            } -> std::same_as<type &>; // assignment
                        {
                            (&val)->~type()
                        }; // destructor
 
                        {
                            val.begin()
                            } -> std::same_as<typename type::iterator>;
                        {
                            val.end()
                            } -> std::same_as<typename type::iterator>;
                        {
                            cval.begin()
                            } -> std::same_as<typename type::const_iterator>;
                        {
                            cval.end()
                            } -> std::same_as<typename type::const_iterator>;
                        {
                            val.cbegin()
                            } -> std::same_as<typename type::const_iterator>;
                        {
                            val.cend()
                            } -> std::same_as<typename type::const_iterator>;
 
                        requires !std::equality_comparable<typename type::value_type> || std::equality_comparable<type>;
 
                        {
                            val.swap(val2)
                            } -> std::same_as<void>;
                        {
                            swap(val, val2)
                            } -> std::same_as<void>;
                        {
                            std::swap(val, val2)
                            } -> std::same_as<void>;
 
                        {
                            val.size()
                            } -> std::same_as<typename type::size_type>;
                        {
                            val.max_size()
                            } -> std::same_as<typename type::size_type>;
                        {
                            val.empty()
                            } -> std::same_as<bool>;
                    };
 
template <typename type>
concept sequence_container =
    requires (type val, type val2, type const cval) {
        requires container<type>;
 
        // construction
        {
            type(typename type::size_type{}, typename type::value_type{})
        };
        {
            type{val2.begin(), val2.end()}
        }; // NOTE that this could be any input iterator:
        {
            type{std::initializer_list<typename type::value_type>{}}
        };
        {
            val = std::initializer_list<typename type::value_type>{}
            } -> std::same_as<type &>;
 
        // assignment NOTE return type is type & for std::string and void for other stl containers:
        {
            val.assign(val2.begin(), val2.end())
        };
        {
            val.assign(std::initializer_list<typename type::value_type>{})
        };
        {
            val.assign(typename type::size_type{}, typename type::value_type{})
        };
 
        // modify container
        // TODO: how do you model this?
        // {val.emplace(typename type::const_iterator{}, ?)} -> std::same_as<typename type::iterator>;
#if SEQAN3_WORKAROUND_GCC_NO_CXX11_ABI
        {
            val.insert(val.begin(), val2.front())
            } -> std::same_as<typename type::iterator>;
        {
            val.insert(val.begin(), typename type::value_type{})
            } -> std::same_as<typename type::iterator>;
 
        // std::string is missing the const_iterator versions for insert in pre-C++11 ABI
        requires detail::is_basic_string_v<type>
                     || requires (type val, type val2)
#else  // ^^^ workaround / no workaround vvv
        requires requires (type val, type val2)
#endif // SEQAN3_WORKAROUND_GCC_NO_CXX11_ABI
        {
            {
                val.insert(val.cbegin(), val2.front())
                } -> std::same_as<typename type::iterator>;
            {
                val.insert(val.cbegin(), typename type::value_type{})
                } -> std::same_as<typename type::iterator>;
            {
                val.insert(val.cbegin(), typename type::size_type{}, typename type::value_type{})
                } -> std::same_as<typename type::iterator>;
            {
                val.insert(val.cbegin(), val2.begin(), val2.end())
                } -> std::same_as<typename type::iterator>;
            {
                val.insert(val.cbegin(), std::initializer_list<typename type::value_type>{})
                } -> std::same_as<typename type::iterator>;
        };
 
#if SEQAN3_WORKAROUND_GCC_NO_CXX11_ABI
        // std::string is missing the const_iterator versions for erase in pre-C++11 ABI
        requires detail::is_basic_string_v<type>
                     || requires (type val)
#else  // ^^^ workaround / no workaround vvv
        requires requires (type val)
#endif // SEQAN3_WORKAROUND_GCC_NO_CXX11_ABI
        {
            {
                val.erase(val.cbegin())
                } -> std::same_as<typename type::iterator>;
            {
                val.erase(val.cbegin(), val.cend())
                } -> std::same_as<typename type::iterator>;
        };
 
        {
            val.push_back(val.front())
            } -> std::same_as<void>;
        {
            val.push_back(typename type::value_type{})
            } -> std::same_as<void>;
        {
            val.pop_back()
            } -> std::same_as<void>;
        {
            val.clear()
            } -> std::same_as<void>;
 
        // access container
        {
            val.front()
            } -> std::same_as<typename type::reference>;
        {
            cval.front()
            } -> std::same_as<typename type::const_reference>;
        {
            val.back()
            } -> std::same_as<typename type::reference>;
        {
            cval.back()
            } -> std::same_as<typename type::const_reference>;
    };
 
template <typename type>
concept random_access_container = requires (type val) {
                                      requires sequence_container<type>;
 
                                      // access container
                                      {
                                          val[0]
                                          } -> std::same_as<typename type::reference>;
                                      {
                                          val.at(0)
                                          } -> std::same_as<typename type::reference>;
 
                                      // modify container
                                      {
                                          val.resize(0)
                                          } -> std::same_as<void>;
                                      {
                                          val.resize(0, typename type::value_type{})
                                          } -> std::same_as<void>;
                                  };
 
template <typename type>
concept reservible_container = requires (type val) {
                                   requires random_access_container<type>;
 
                                   {
                                       val.capacity()
                                       } -> std::same_as<typename type::size_type>;
                                   {
                                       val.reserve(0)
                                       } -> std::same_as<void>;
                                   {
                                       val.shrink_to_fit()
                                       } -> std::same_as<void>;
                               };
 
} // namespace seqan3