ADVstd.h

/**
 * ADVstd - Minimalist entities from the Standard Library
 *
 * Copyright (C) 2018 Sebastien Andrivet [https://github.com/andrivet/]
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef ADVSTD_H
#define ADVSTD_H

// Default placement new
inline void* operator new(size_t, void* p) noexcept { return p; }
inline void* operator new[](size_t, void* p) noexcept { return p; }

namespace adv {

using size_t = decltype(sizeof(int));
using nullptr_t = decltype(nullptr);

// Not in the standard, but useful
template <typename T, size_t N>
constexpr size_t count_of(T const (&)[N]) noexcept { return N; }

template<typename T> struct remove_reference { using type = T; };
template<typename T> struct remove_reference<T&>  { using type = T; };
template<typename T> struct remove_reference<T&&> { using type = T; };

template<typename T, T v>
struct integral_constant
{
    static constexpr const T value = v;
    typedef T value_type;
    typedef integral_constant type;
    inline constexpr explicit operator value_type() const noexcept {return value;}
    inline constexpr value_type operator ()() const noexcept {return value;}
};

template<bool B>
using bool_constant = integral_constant<bool, B>;

using true_type  = bool_constant<true>;
using false_type = bool_constant<false>;

template<typename T> struct is_lvalue_reference     : false_type {};
template<typename T> struct is_lvalue_reference<T&> : true_type {};

template<typename T>
struct is_void { static const bool value = false;};
template<> struct is_void<void> { static const bool value = true; };

template<typename...> using void_t = void;

template<class T, class U>
struct is_same : false_type {};

template<class T>
struct is_same<T, T> : true_type {};

template<typename T>
inline typename remove_reference<T>::type&& move(T&& t) noexcept
{
    typedef typename remove_reference<T>::type U;
    return static_cast<U&&>(t);
}

template<typename T>
inline T&& forward(typename remove_reference<T>::type& t) noexcept
{
    return static_cast<T&&>(t);
}

template<typename T>
inline T&& forward(typename remove_reference<T>::type&& t) noexcept
{
    static_assert(!is_lvalue_reference<T>::value, "can not forward an rvalue as an lvalue");
    return static_cast<T&&>(t);
}

template<typename T, typename> struct alr_ { using type = T; };
template<typename T>           struct alr_<T, void_t<T&>> { using type = T&; };
template<typename T, typename> struct arr_ { using type = T; };
template<typename T>           struct arr_<T, void_t<T&&>> { using type = T&&; };
template<typename T, typename> struct ap_ { using type = T; };
template<typename T>           struct ap_<T, void_t<T*>> { using type = T*; };

template<typename T>           struct add_lvalue_reference: alr_<T, void> {};
template<typename T>           struct add_rvalue_reference_t: arr_<T, void> {};
template<typename T>           struct add_pointer: ap_<T, void> {};


template<typename T> void swap(T& a, T& b) { T c{move(a)}; a = move(b); b = move(c); }

template<typename T> auto declval() noexcept -> add_rvalue_reference_t<T>;

template<bool, typename T = void> struct enable_if {};
template<typename T> struct enable_if<true, T> { using type = T; };
template< bool B, typename T = void > using enable_if_t = typename enable_if<B, T>::type;

template<typename I, typename O>
inline O copy(I first, I last, O d_first)
{
    while(first != last)
        *d_first++ = *first++;
    return d_first;
}

} // namespace adv

#endif