source: src/Common/Stats/Base.h

//
// Cforall Version 1.0.0 Copyright (C) 2019 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// Heap.h --
//
// Author           : Thierry Delisle
// Created On       : Fri Mar 03 14:53:53 2019
// Last Modified By :
// Last Modified On :
// Update Count     :
//

#pragma once

#include <cstdint>
#include <iostream>

namespace Stats {
        namespace Base {
                class TreeImpl;

                struct TreeTop {
                        TreeImpl * head = nullptr;
                        TreeImpl * tail = nullptr;

                        inline void append(TreeImpl * node);
                };

                template<typename func_t>
                void ForAll(TreeTop & range, std::size_t level, func_t func, bool destroy = false);

                class TreeImpl {
                public:
                        virtual void print(std::ostream &) = 0;

                        const char * const name;
                        TreeImpl(const char * const name) : name(name) {}

                protected:
                        virtual ~TreeImpl() = default;

                        TreeImpl * next = nullptr;
                        TreeTop children;

                        friend struct TreeTop;

                        template<typename func_t>
                        friend void ForAll(TreeTop & range, std::size_t level, func_t func, bool destroy);
                };

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

                template<typename func_t>
                inline void ForAll(TreeTop & range, std::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<TreeTop & top>
                class Tree : public TreeImpl {
                public:
                        Tree(const char * const name) : TreeImpl{name} {
                                top.append(this);
                        }

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