container.h

// -*- mode: c++; tab-width: 4; indent-tabs-mode: t; eval: (progn (c-set-style "stroustrup") (c-set-offset 'innamespace 0)); -*-
// vi:set ts=4 sts=4 sw=4 noet :
// Copyright 2015, The TPIE development team
// 
// This file is part of TPIE.
// 
// TPIE is free software: you can redistribute it and/or modify it under
// the terms of the GNU Lesser General Public License as published by the
// Free Software Foundation, either version 3 of the License, or (at your
// option) any later version.
// 
// TPIE is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
// License for more details.
// 
// You should have received a copy of the GNU Lesser General Public License
// along with TPIE.  If not, see <http://www.gnu.org/licenses/>

#ifndef __TPIE_PIPELINING_PIPE_CONTAINER_H__
#define __TPIE_PIPELINING_PIPE_CONTAINER_H__

#include <type_traits>
#include <memory>
#include <typeinfo>

namespace tpie {
namespace pipelining {

template <typename T>
T & move_if_movable(typename std::remove_reference<T>::type & t,
            typename std::enable_if<!std::is_move_constructible<T>::value>::type* = 0) {
    return t;
}

template <typename T>
T && move_if_movable(typename std::remove_reference<T>::type & t,
            typename std::enable_if<std::is_move_constructible<T>::value>::type* = 0) {
    return static_cast<T&&>(t);
}

template <typename T>
T & move_if_movable_rvalue(typename std::remove_reference<T>::type & t,
            typename std::enable_if<
                !std::is_move_constructible<T>::value ||
                !std::is_rvalue_reference<T>::value
            >::type* = 0) {
    return t;
}

template <typename T>
T && move_if_movable_rvalue(typename std::remove_reference<T>::type & t,
            typename std::enable_if<
                std::is_move_constructible<T>::value &&
                std::is_rvalue_reference<T>::value
            >::type* = 0) {
    return static_cast<T&&>(t);
}


template <typename ... TT>
class container {};

template <typename T, typename ... TT>
struct container<T, TT...> : public container<TT...> {
    container(const container &) = delete;
    container() = delete;

    template <typename T2, typename ... TT2>
    container(T2 && t, TT2 && ... tt)
        : container<TT...>(std::forward<TT2>(tt)...)
        , v(move_if_movable_rvalue<T2&&>(t)) {}

    container(container && o)
        : container<TT...>(std::forward<container<TT...> >(o))
        , v(move_if_movable<T>(o.v)) {}

    T v;
};

namespace bits {
template <int i, typename T, typename ...TT>
struct get_impl {
    typedef typename get_impl<i-1, TT...>::type type;
    static type & get(container<T, TT...> & cc) {return get_impl<i-1, TT...>::get(cc);}
    static const type & get(const container<T, TT...> & cc) {return get_impl<i-1, TT...>::get(cc);}
};

template <typename T, typename ...TT>
struct get_impl<0, T, TT...> {
    typedef T type;
    static type & get(container<T, TT...> & cc) {return cc.v;}
    static const type & get(const container<T, TT...> & cc) {return cc.v;}
};
} //namespace bits


template <int i, typename ...T>
typename bits::get_impl<i, T...>::type & get(container<T...> & c) {
    return bits::get_impl<i, T...>::get(c);
}

template <int i, typename ...T>
const typename bits::get_impl<i, T...>::type & get(const container<T...> & c) {
    return bits::get_impl<i, T...>::get(c);
}

namespace bits {
template<int ... S>
struct dispatch {
    template <typename F, typename ... T1, typename ... T2>
    static F run_move(container<T1...> & t, T2 &&... o) {
        return F(std::move(o)..., move_if_movable<T1>(get<S>(t))...);
    }

    template <typename F, typename ... T1, typename ... T2>
    static F run_copy(container<T1...> & t, T2 &&... o) {
        return F(std::move(o)..., get<S>(t)...);
    }
};

template<int N, int ...S>
struct dispatch_gen : dispatch_gen<N-1, N-1, S...> { };

template<int ...S>
struct dispatch_gen<0, S...> {
    typedef dispatch<S...> type;
};

} //namespace bits


template <typename F, typename ... T1, typename ... T2>
F container_construct(container<T1...> & cont, T2 && ... a) {
    return bits::dispatch_gen<sizeof...(T1)>::type::template run_move<F>(cont, std::move(a)...);
}

template <typename F, typename ... T1, typename ... T2>
F container_construct_copy(container<T1...> & cont, T2 && ... a) {
    return bits::dispatch_gen<sizeof...(T1)>::type::template run_copy<F>(cont, std::move(a)...);
}

class bad_any_noncopyable_copy: public std::exception {
public:
    const char * what() const noexcept override {return "bad any_noncopyable copy";}
};


namespace bits {

class any_noncopyable_cont_base {
public:
    virtual ~any_noncopyable_cont_base() {};
    virtual const std::type_info & type() const {
        return typeid(void);
    }
    virtual any_noncopyable_cont_base * copy() const = 0;
};

template <typename T, bool can_copy = std::is_copy_constructible<T>::value>
class any_noncopyable_cont: public any_noncopyable_cont_base {
public:
    any_noncopyable_cont(T value): value(move_if_movable<T>(value)) {}
    T value;
    const std::type_info & type() const override {
        return typeid(value);
    }

    any_noncopyable_cont_base * copy() const override {
        throw bad_any_noncopyable_copy();
    }
};

template <typename T>
class any_noncopyable_cont<T, true>: public any_noncopyable_cont_base {
public:
    any_noncopyable_cont(T value): value(move_if_movable<T>(value)) {}
    T value;
    const std::type_info & type() const override {
        return typeid(value);
    }

    any_noncopyable_cont_base * copy() const override {
        return new any_noncopyable_cont<T, true>(value);
    }
};


} //namespace bits

class bad_any_noncopyable_cast: public std::bad_cast {
public:
    const char * what() const noexcept override {return "bad any_noncopyable cast";}
};
    
class any_noncopyable {
public:
    template <typename T>
    explicit any_noncopyable(T t) {
        cont = std::unique_ptr<bits::any_noncopyable_cont_base>(
            new bits::any_noncopyable_cont<T>(move_if_movable<T>(t)));
    }
    
    any_noncopyable() = default;
    any_noncopyable(const any_noncopyable &) = delete;
    any_noncopyable(any_noncopyable &&) = default;
    any_noncopyable & operator=(const any_noncopyable & o) = delete;
    any_noncopyable & operator=(any_noncopyable && o) = default;
    
    template <typename T>
    any_noncopyable & operator=(T t) {
        cont = std::unique_ptr<bits::any_noncopyable_cont_base>(
            new bits::any_noncopyable_cont<T>(move_if_movable<T>(t)));
        return *this;
    }
    
    explicit operator bool() {return (bool)cont;}
    
    void reset() {cont.reset();}
    
    any_noncopyable copy() const {
        return any_noncopyable(cont->copy());
    }

    template <typename T>
    friend const T & any_cast(const any_noncopyable & a);
    
    template <typename T>
    friend T & any_cast(any_noncopyable & a);
    
    friend void swap(any_noncopyable & l, any_noncopyable & r);

    const std::type_info & type() const {
        if (!cont) return typeid(void);
        auto val = cont.get();
        return val->type();
    }
private:
    explicit any_noncopyable(bits::any_noncopyable_cont_base * elm)
        : cont(elm) {}
    
    std::unique_ptr<bits::any_noncopyable_cont_base> cont;
};

template <typename T>
const T & any_cast(const any_noncopyable & a) {
    if (!a.cont) throw bad_any_noncopyable_cast();
    auto val = a.cont.get();
    if (typeid(*val) != typeid(bits::any_noncopyable_cont<T>)) throw bad_any_noncopyable_cast();
    return static_cast<const bits::any_noncopyable_cont<T>*>(val)->value;
}

template <typename T>
T & any_cast(any_noncopyable & a) {
    if (!a.cont) throw bad_any_noncopyable_cast();
    auto val = a.cont.get();
    if (typeid(*val) != typeid(bits::any_noncopyable_cont<T>)) throw bad_any_noncopyable_cast();
    return static_cast<bits::any_noncopyable_cont<T>*>(val)->value;
}

inline void swap(any_noncopyable & l, any_noncopyable & r) {std::swap(l.cont, r.cont);}

} //namespace pipelining
} //namespace tpie
#endif //__TPIE_PIPELINING_PIPE_CONTAINER_H__