促进融合适应声明模板化的自我参照结构 [英] Boost Fusion adapt declaration for a templated self referential structure

问题描述

我想声明一个自我指涉的树一样，是对数据的结构可以容纳的类型模板结构。我遇到编译错误，试图声明提振融合模板适应定义这种结构时。谁能帮助？

 的#include＆LT;＆iostream的GT;
＃包括LT＆;串GT;
＃包括LT＆;内存和GT;
＃包括LT＆;矢量＆GT;＃包括LT＆;升压/ lexical_cast.hpp＆GT;
＃包括LT＆;升压/ dynamic_bitset.hpp＆GT;＃包括LT＆;升压/融合/调整/结构/ adapt_struct.hpp＆GT;
＃包括LT＆;升压/融合/有/ adapt_struct.hpp＆GT;一个结构
{
    INT a_val;
    A（）：a_val（0）{}
    A（INT一个）：a_val（一）{}    朋友的std :: ostream的＆放大器;运营商的LT;≤（的std :: ostream的和放大器;输出，A和a_obj）
    {
        输出＆LT;＆LT; a_obj.a_val;
        返回输出;
    }
};模板＆LT; typename的tree_type_t＆GT;
结构simple_tree_t
{
    simple_tree_t（）{}
    simple_tree_t（tree_type_t t_obj）：tree_data（t_obj）{}
    tree_type_t tree_data;    的std ::矢量＆lt;的std :: shared_ptr的＆LT; tree_type_t＆GT; ＆GT; sub_tree;    typedef的类型名称的std ::矢量＆lt;的std :: shared_ptr的＆LT; tree_type_t＆GT; ＆GT; ::迭代器sub_tree_iterator;    sub_tree_iterator sub_tree_begin（）{返回sub_tree.begin（）; }
    sub_tree_iterator sub_tree_end（）{返回sub_tree.end（）; }    朋友的std :: ostream的＆放大器;运营商的LT;≤（的std :: ostream的和放大器;输出，simple_tree_t＆安培;树）
    {
        输出＆LT;＆LT; tree.tree_data;
        的std :: for_each的（tree.sub_tree_begin（）
                        tree.sub_tree_end（），
                        （[安培]（常量的std :: shared_ptr的＆LT; A＆F）的温度{
                            输出＆LT;＆LT; *F;
                            }））;
        返回输出;
    }
};BOOST_FUSION_ADAPT_STRUCT（A，
                                （INT，a_val））BOOST_FUSION_ADAPT_TPL_STRUCT（（tree_type_t）
                                （simple_tree_t）（tree_type_t）
                                （tree_type_t，tree_data）
                                （类型名称的std ::矢量＆lt;的std :: shared_ptr的＆LT; tree_type_t＆GT;＆GT;，sub_tree））INT主要（无效）
{
    simple_tree_t＆LT; A＆GT; t_i，t_o;    t_i.tree_data = A（10）;
    t_i.sub_tree.push_back（性病:: make_shared＆LT; A＆GT;（A（20）））;
    t_i.sub_tree.push_back（性病:: make_shared＆LT; A＆GT;（A（30）））;    性病::法院LT＆;＆LT; t_i＆LT;＆LT;的std :: ENDL;    返回0;
}
 

解决方案

@cv_and_he是当场上; 住在Coliru

  BOOST_FUSION_ADAPT_TPL_STRUCT（（tree_type_t）
                                （simple_tree_t）（tree_type_t）
                                （tree_type_t，tree_data）
                                （类型名称的std ::矢量＆lt;的std :: shared_ptr的＆LT; tree_type_t＆GT;＆GT;，sub_tree））
 

I am trying to declare a self referential tree like structure that is templated on the type of data that the struct can hold. I am running into compilation errors, when trying to declare the boost fusion template adapt definition for this structure. Can anyone help ?

#include <iostream>
#include <string>
#include <memory>
#include <vector>

#include <boost/lexical_cast.hpp>
#include <boost/dynamic_bitset.hpp>

#include <boost/fusion/adapted/struct/adapt_struct.hpp>
#include <boost/fusion/include/adapt_struct.hpp>

struct A
{
    int a_val;
    A() : a_val(0) {}
    A(int a) : a_val(a) {}

    friend std::ostream& operator<<(std::ostream &output, A &a_obj)
    {
        output << a_obj.a_val;
        return output;
    }
};

template <typename tree_type_t>
struct simple_tree_t
{
    simple_tree_t() {}
    simple_tree_t( tree_type_t t_obj):tree_data(t_obj) {}
    tree_type_t tree_data;

    std::vector < std::shared_ptr < tree_type_t > > sub_tree;

    typedef typename std::vector < std::shared_ptr < tree_type_t > >::iterator sub_tree_iterator;

    sub_tree_iterator sub_tree_begin() { return sub_tree.begin(); }
    sub_tree_iterator sub_tree_end() { return sub_tree.end(); }

    friend std::ostream& operator<<(std::ostream &output, simple_tree_t &tree)
    {
        output << tree.tree_data;
        std::for_each ( tree.sub_tree_begin(), 
                        tree.sub_tree_end(), 
                        ([&](const std::shared_ptr < A > f){
                            output << *f;
                            }) );
        return output;
    }
};

BOOST_FUSION_ADAPT_STRUCT ( A,
                                (int , a_val) )

BOOST_FUSION_ADAPT_TPL_STRUCT ( (tree_type_t)
                                (simple_tree_t) (tree_type_t)
                                (tree_type_t, tree_data)
                                (typename std::vector < std::shared_ptr < tree_type_t > > , sub_tree) )

int main(void)
{
    simple_tree_t<A> t_i, t_o;

    t_i.tree_data = A(10);
    t_i.sub_tree.push_back(std::make_shared<A>(A(20)));
    t_i.sub_tree.push_back(std::make_shared<A>(A(30)));

    std::cout << t_i << std::endl;

    return 0;
}

解决方案

@cv_and_he is spot on; Live On Coliru

BOOST_FUSION_ADAPT_TPL_STRUCT ( (tree_type_t),
                                (simple_tree_t) (tree_type_t),
                                (tree_type_t, tree_data)
                                (typename std::vector < std::shared_ptr < tree_type_t > > , sub_tree) )

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