source: doc/papers/general/evaluation/cpp-stack.hpp@ e84382b

#pragma once
#include <utility>

template<typename T> struct stack {
        struct node {
                T value;
                node * next;
                node( const T & v, node * n = nullptr ) : value( v ), next( n ) {}
        };
        node * head;

        stack() : head( nullptr ) {}
        stack( const stack<T> & o ) { copy( o ); }
        stack( stack<T> && o ) : head( o.head ) { o.head = nullptr; }

        void clear() {
                for ( node * next = head; next; ) {
                        node * crnt = next;
                        next = crnt->next;
                        delete crnt;
                }
                head = nullptr;
        }

        void copy( const stack<T> & o ) {
                node ** crnt = &head;
                for ( node * next = o.head; next; next = next->next ) {
                        *crnt = new node{ next->value }; /***/
                        crnt = &(*crnt)->next;
                }
                *crnt = nullptr;
        }

        ~stack() { clear(); }

        stack & operator= ( const stack<T> & o ) {
                if ( this == &o ) return *this;
                clear();
                copy( o );
                return *this;
        }

        bool empty() const { return head == nullptr; }

        void push( const T & value ) { head = new node{ value, head };  /***/ }

        T pop() {
                node * n = head;
                head = n->next;
                T v = std::move( n->value );
                delete n;
                return v;
        }
};