source: src/Common/Stats/Base.h@ 8e70823

#pragma once

#include <string>

namespace Stats {
        namespace Base {
                class TreeImpl {
                public:
                        struct Top {
                                TreeImpl * head = nullptr;
                                TreeImpl * tail = nullptr;

                                void append(TreeImpl * node) {
                                        if(!head) { head = node; }
                                        else      { tail->next = node;}
                                        tail = node;
                                }
                        };

                        virtual void print(std::ostream &) = 0;

                        const std::string name;
                        TreeImpl(const std::string & name) : name(name) {}

                protected:
                        virtual ~TreeImpl() = default;

                        TreeImpl * next = nullptr;
                        Top children;

                        template<typename func_t>
                        friend void ForAll(TreeImpl::Top & range, size_t level, func_t func, bool destroy = false);
                };

                template<typename func_t>
                inline void ForAll(TreeImpl::Top & range, size_t level, func_t func, bool destroy) {
                        auto it = range.head;
                        while(it) {
                                auto next = it->next;
                                func(it, level);
                                ForAll(it->children, level + 1, func);
                                if(destroy) delete it;
                                it = next;
                        }
                }

                template<TreeImpl::Top & top>
                class Tree : public TreeImpl {
                public:
                        Tree(const std::string & name) : TreeImpl{name} {
                                top.append(this);
                        }

                        Tree(const std::string & name, Tree * parent) : TreeImpl{name} {
                                parent->children.append(this);
                        }
                protected:
                        virtual ~Tree() = default;
                };
        }
}