c++-模板元编程TypeList进阶操作Select

c+±模板元编程TypeList定义及基本操作

c+±模板元编程ValueList定义及基本操作

#include "def.h"
#include "valueList.h"

// select
template
struct Select_;

template
using Select_t = typename Select_::type;

template
struct Select_> {
    using type = TypeList...>;
};

void select_test() {
    using SignedIntegralTypes = TypeList;
    using ReversedSignedIntegralTypes = Select_t>;
    cout << boost::typeindex::type_id_with_cvr().pretty_name() << endl;
}

// select 实战 实现 insertionSort; 排序 index索引, 使用 Select生成目标结果

// 有序索引列表插入
template typename Compare, typename Elem, bool = IsEmpty_v>
struct InsertSortedIndex_ {
    using Front = Front_t;
    using Tail = typename conditional_t<
            Compare::value,
            Identity,
            InsertSortedIndex_, Compare, Elem>>::type;

    using Head = conditional_t<
            Compare::value,
            Elem,
            Front>;

    using type = PushFront_t;
};

template typename Compare, typename Elem>
using InsertSortedIndex_t = typename InsertSortedIndex_::type;

template typename Compare, typename Elem>
struct InsertSortedIndex_ {
    using type = PushFront_t;
};

// 排序索引
template typename Compare, bool = IsEmpty_v>
struct InsertionIndexSort_ {
    using Front = Front_t;
    using Tail = typename InsertionIndexSort_, Compare>::type;
    using type = InsertSortedIndex_t;
};

template typename Compare>
struct InsertionIndexSort_ {
    using type = Indices;
};

template typename Compare, bool = IsEmpty_v>
struct NewInsertionSort_ {
    using NewIndexes = typename InsertionIndexSort_::type;
    using type = Select_t;
};
template typename Compare>
using NewInsertionSort_t = typename NewInsertionSort_::type;


template typename Compare>
struct NewInsertionSort_ {
    using type = List;
};

template
struct IndexCompare {
	// 按照类型的大小排序
    constexpr static auto value = sizeof(NthElem_t) < sizeof(NthElem_t);
};

template
auto makeTypeListIndices(index_sequence) {
    return ValueList{};
}

void insertionSort_test() {
    using SL = TypeList;
    using Indices = decltype(makeTypeListIndices(make_index_sequence>()));
    // 排序
    using Sortted = NewInsertionSort_t;
    cout << boost::typeindex::type_id_with_cvr().pretty_name() << endl;
}

int main() {
    select_test();
    insertionSort_test();
}