concept.hpp

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// -----------------------------------------------------------------------------------------------------
// Copyright (c) 2006-2020, Knut Reinert & Freie Universität Berlin
// Copyright (c) 2016-2020, 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 <initializer_list>
#include <iterator>
#include <type_traits>
 
// remove if is_basic_string is not needed anymore
#include <string>
 
#include <seqan3/std/iterator>
#include <seqan3/std/concepts>
 
// TODO:
// * remove is_basic_string
// * remove #include <string> in this file
// once the gcc bug [1] was fixed AND we require at least a gcc version which
// contains this fix
//
// [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83328
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;
 
 
} // seqan3::detail
 
namespace seqan3
{
 
template <typename type>
SEQAN3_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>;
    { it } -> typename type::const_iterator; // NOTE check whether iterator is const convertible
 
    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{}          } -> type;   // default constructor
    { type{type{}}    } -> type;   // copy/move constructor
    { val = val2      } -> type &; // assignment
    { (&val)->~type() };           // destructor
 
    { val.begin()     } -> typename type::iterator;
    { val.end()       } -> typename type::iterator;
    { cval.begin()    } -> typename type::const_iterator;
    { cval.end()      } -> typename type::const_iterator;
    { val.cbegin()    } -> typename type::const_iterator;
    { val.cend()      } -> typename type::const_iterator;
 
    requires !std::equality_comparable<typename type::value_type> || std::equality_comparable<type>;
 
    { val.swap(val2)  } -> void;
    { swap(val, val2) } -> void;
    { std::swap(val, val2) } -> void;
 
    { val.size()      } -> typename type::size_type;
    { val.max_size()  } -> typename type::size_type;
    { val.empty()     } -> bool;
};
 
template <typename type>
SEQAN3_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>{}      } -> 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{}, ?                                   } -> typename type::iterator;
    { val.insert(val.cbegin(), val2.front())                                           } -> typename type::iterator;
    { val.insert(val.cbegin(), typename type::value_type{})                            } -> typename type::iterator;
    { val.insert(val.cbegin(), typename type::size_type{}, typename type::value_type{})} -> typename type::iterator;
    { val.insert(val.cbegin(), val2.begin(), val2.end())                               } -> typename type::iterator;
    requires detail::is_basic_string_v<type> || requires(type val)
    {
        // TODO this function is not defined on strings (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83328)
        { val.insert(val.cbegin(), std::initializer_list<typename type::value_type>{}) } -> typename type::iterator;
    };
 
    { val.erase(val.cbegin())                                                          } -> typename type::iterator;
    { val.erase(val.cbegin(), val.cend())                                              } -> typename type::iterator;
 
    { val.push_back(val.front())                                                       } -> void;
    { val.push_back(typename type::value_type{})                                       } -> void;
    { val.pop_back()                                                                   } -> void;
    { val.clear()                                                                      } -> void;
 
    // access container
    { val.front()  } -> typename type::reference;
    { cval.front() } -> typename type::const_reference;
    { val.back()   } -> typename type::reference;
    { cval.back()  } -> typename type::const_reference;
};
 
template <typename type>
SEQAN3_CONCEPT random_access_container = requires (type val)
{
    requires sequence_container<type>;
 
    // access container
    { val[0]    } -> typename type::reference;
    { val.at(0) } -> typename type::reference;
 
    // modify container
    { val.resize(0)                              } -> void;
    { val.resize(0, typename type::value_type{}) } -> void;
};
 
template <typename type>
SEQAN3_CONCEPT reservible_container = requires (type val)
{
    requires random_access_container<type>;
 
    { val.capacity()      } -> typename type::size_type;
    { val.reserve(0)      } -> void;
    { val.shrink_to_fit() } -> void;
};
 
 
} // namespace seqan3