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/*
====================================================================
A Smart Pointer to IMPLementation (i.e. Smart PIMPL or just SPIMPL).
====================================================================
Version: 1.2
Latest version:
https://github.com/oliora/samples/blob/master/spimpl.h
Rationale and description:
http://oliora.github.io/2015/12/29/pimpl-and-rule-of-zero.html
Copyright (c) 2015 Andrey Upadyshev (oliora@gmail.com)
Distributed under the Boost Software License, Version 1.0.
See http://www.boost.org/LICENSE_1_0.txt
Changes history
---------------
v1.2:
- const correctness
v1.1:
- auto_ptr support is disabled by default for C++17 compatibility
v1.0:
- Released
*/
#ifndef SPIMPL_H_
#define SPIMPL_H_
#include <memory>
#include <type_traits>
#include <cassert>
#if defined _MSC_VER && _MSC_VER < 1900 // MS Visual Studio before VS2015
#define SPIMPL_NO_CPP11_NOEXCEPT
#define SPIMPL_NO_CPP11_CONSTEXPR
#define SPIMPL_NO_CPP11_DEFAULT_MOVE_SPEC_FUNC
#endif
#if ! defined SPIMPL_NO_CPP11_NOEXCEPT
#define SPIMPL_NOEXCEPT noexcept
#else
#define SPIMPL_NOEXCEPT
#endif
#if ! defined SPIMPL_NO_CPP11_CONSTEXPR
#define SPIMPL_CONSTEXPR constexpr
#else
#define SPIMPL_CONSTEXPR
#endif
// define SPIMPL_HAS_AUTO_PTR to enable constructor and assignment operator that accept std::auto_ptr
// TODO: auto detect std::auto_ptr support
namespace spimpl {
namespace details {
template<class T>
T *default_copy(T *src)
{
static_assert(sizeof(T) > 0, "default_copy cannot copy incomplete type");
static_assert(!std::is_void<T>::value, "default_copy cannot copy incomplete type");
return new T(*src);
}
template<class T>
void default_delete(T *p) SPIMPL_NOEXCEPT
{
static_assert(sizeof(T) > 0, "default_delete cannot delete incomplete type");
static_assert(!std::is_void<T>::value, "default_delete cannot delete incomplete type");
delete p;
}
template<class T>
struct default_deleter {
using type = void (*)(T*);
};
template<class T>
using default_deleter_t = typename default_deleter<T>::type;
template<class T>
struct default_copier {
using type = T* (*)(T*);
};
template<class T>
using default_copier_t = typename default_copier<T>::type;
template<class T, class D, class C>
struct is_default_manageable: public std::integral_constant<bool,
std::is_same<D, default_deleter_t<T>>::value &&
std::is_same<C, default_copier_t<T>>::value
> {};
}
template<class T, class Deleter = details::default_deleter_t<T>, class Copier = details::default_copier_t<T>>
class impl_ptr
{
private:
static_assert(!std::is_array<T>::value, "impl_ptr specialization for arrays is not implemented");
struct dummy_t_ {int dummy__;};
public:
using pointer = T*;
using const_pointer = typename std::add_const<T>::type *;
using reference = T&;
using const_reference = typename std::add_const<T>::type &;
using element_type = T;
using copier_type = typename std::decay<Copier>::type;
using deleter_type = typename std::decay<Deleter>::type;
using unique_ptr_type = std::unique_ptr<T, deleter_type>;
using is_default_manageable = details::is_default_manageable<T, deleter_type, copier_type>;
SPIMPL_CONSTEXPR impl_ptr() SPIMPL_NOEXCEPT
: ptr_(nullptr, deleter_type{}), copier_(copier_type{}) {}
SPIMPL_CONSTEXPR impl_ptr(std::nullptr_t) SPIMPL_NOEXCEPT
: impl_ptr() {}
template<class D, class C>
impl_ptr(pointer p, D&& d, C&& c,
typename std::enable_if<
std::is_convertible<D, deleter_type>::value
&& std::is_convertible<C, copier_type>::value,
dummy_t_
>::type = dummy_t_()) SPIMPL_NOEXCEPT
: ptr_(std::move(p), std::forward<D>(d)), copier_(std::forward<C>(c)) {}
template<class U>
impl_ptr(U *u,
typename std::enable_if<
std::is_convertible<U*, pointer>::value
&& is_default_manageable::value,
dummy_t_
>::type = dummy_t_()) SPIMPL_NOEXCEPT
: impl_ptr(u, &details::default_delete<T>, &details::default_copy<T>) {}
impl_ptr(const impl_ptr& r)
: impl_ptr(r.clone()) {}
#ifndef SPIMPL_NO_CPP11_DEFAULT_MOVE_SPEC_FUNC
impl_ptr(impl_ptr&& r) SPIMPL_NOEXCEPT = default;
#else
impl_ptr(impl_ptr&& r) SPIMPL_NOEXCEPT
: ptr_(std::move(r.ptr_)), copier_(std::move(r.copier_)) {}
#endif
#ifdef SPIMPL_HAS_AUTO_PTR
template<class U>
impl_ptr(std::auto_ptr<U>&& u,
typename std::enable_if<
std::is_convertible<U*, pointer>::value
&& is_default_manageable::value,
dummy_t_
>::type = dummy_t_()) SPIMPL_NOEXCEPT
: ptr_(u.release(), &details::default_delete<T>), copier_(&details::default_copy<T>) {}
#endif
template<class U>
impl_ptr(std::unique_ptr<U>&& u,
typename std::enable_if<
std::is_convertible<U*, pointer>::value
&& is_default_manageable::value,
dummy_t_
>::type = dummy_t_()) SPIMPL_NOEXCEPT
: ptr_(u.release(), &details::default_delete<T>), copier_(&details::default_copy<T>) {}
template<class U, class D, class C>
impl_ptr(std::unique_ptr<U, D>&& u, C&& c,
typename std::enable_if<
std::is_convertible<U*, pointer>::value
&& std::is_convertible<D, deleter_type>::value
&& std::is_convertible<C, copier_type>::value,
dummy_t_
>::type = dummy_t_()) SPIMPL_NOEXCEPT
: ptr_(std::move(u)), copier_(std::forward<C>(c)) {}
template<class U, class D, class C>
impl_ptr(impl_ptr<U, D, C>&& u,
typename std::enable_if<
std::is_convertible<U*, pointer>::value
&& std::is_convertible<D, deleter_type>::value
&& std::is_convertible<C, copier_type>::value,
dummy_t_
>::type = dummy_t_()) SPIMPL_NOEXCEPT
: ptr_(std::move(u.ptr_)), copier_(std::move(u.copier_)) {}
impl_ptr& operator= (const impl_ptr& r)
{
if (this == &r)
return *this;
return operator=(r.clone());
}
#ifndef SPIMPL_NO_CPP11_DEFAULT_MOVE_SPEC_FUNC
impl_ptr& operator= (impl_ptr&& r) SPIMPL_NOEXCEPT = default;
#else
impl_ptr& operator= (impl_ptr&& r) SPIMPL_NOEXCEPT {
ptr_ = std::move(r.ptr_);
copier_ = std::move(r.copier_);
return *this;
}
#endif
template<class U, class D, class C>
typename std::enable_if<
std::is_convertible<U*, pointer>::value
&& std::is_convertible<D, deleter_type>::value
&& std::is_convertible<C, copier_type>::value,
impl_ptr&
>::type operator= (impl_ptr<U, D, C>&& u) SPIMPL_NOEXCEPT
{
ptr_ = std::move(u.ptr_);
copier_ = std::move(u.copier_);
return *this;
}
template<class U, class D, class C>
typename std::enable_if<
std::is_convertible<U*, pointer>::value
&& std::is_convertible<D, deleter_type>::value
&& std::is_convertible<C, copier_type>::value,
impl_ptr&
>::type operator= (const impl_ptr<U, D, C>& u)
{
return operator=(u.clone());
}
//
#ifdef SPIMPL_HAS_AUTO_PTR
template<class U>
typename std::enable_if<
std::is_convertible<U*, pointer>::value
&& is_default_manageable::value,
impl_ptr&
>::type operator= (std::auto_ptr<U>&& u) SPIMPL_NOEXCEPT
{
return operator=(impl_ptr(std::move(u)));
}
#endif
template<class U>
typename std::enable_if<
std::is_convertible<U*, pointer>::value
&& is_default_manageable::value,
impl_ptr&
>::type operator= (std::unique_ptr<U>&& u) SPIMPL_NOEXCEPT
{
return operator=(impl_ptr(std::move(u)));
}
impl_ptr clone() const
{
return impl_ptr(
ptr_ ? copier_(ptr_.get()) : nullptr,
ptr_.get_deleter(),
copier_);
}
reference operator*() { return *ptr_; }
const_reference operator*() const { return *ptr_; }
pointer operator->() SPIMPL_NOEXCEPT { return get(); }
const_pointer operator->() const SPIMPL_NOEXCEPT { return get(); }
pointer get() SPIMPL_NOEXCEPT { return ptr_.get(); }
const_pointer get() const SPIMPL_NOEXCEPT { return ptr_.get(); }
void swap(impl_ptr& u) SPIMPL_NOEXCEPT
{
using std::swap;
ptr_.swap(u.ptr_);
swap(copier_, u.copier_);
}
pointer release() SPIMPL_NOEXCEPT { return ptr_.release(); }
unique_ptr_type release_unique() SPIMPL_NOEXCEPT { return std::move(ptr_); }
explicit operator bool() const SPIMPL_NOEXCEPT { return static_cast<bool>(ptr_); }
typename std::remove_reference<deleter_type>::type& get_deleter() SPIMPL_NOEXCEPT { return ptr_.get_deleter(); }
const typename std::remove_reference<deleter_type>::type& get_deleter() const SPIMPL_NOEXCEPT { return ptr_.get_deleter(); }
typename std::remove_reference<copier_type>::type& get_copier() SPIMPL_NOEXCEPT { return copier_; }
const typename std::remove_reference<copier_type>::type& get_copier() const SPIMPL_NOEXCEPT { return copier_; }
private:
unique_ptr_type ptr_;
copier_type copier_;
};
template<class T, class D, class C>
inline void swap(impl_ptr<T, D, C>& l, impl_ptr<T, D, C>& r) SPIMPL_NOEXCEPT
{
l.swap(r);
}
template <class T1, class D1, class C1, class T2, class D2, class C2>
inline bool operator==(const impl_ptr<T1, D1, C1>& l, const impl_ptr<T2, D2, C2>& r)
{
return l.get() == r.get();
}
template <class T1, class D1, class C1, class T2, class D2, class C2>
inline bool operator!=(const impl_ptr<T1, D1, C1>& l, const impl_ptr<T2, D2, C2>& r)
{
return !(l == r);
}
template <class T1, class D1, class C1, class T2, class D2, class C2>
inline bool operator< (const impl_ptr<T1, D1, C1>& l, const impl_ptr<T2, D2, C2>& r)
{
using P1 = typename impl_ptr<T1, D1, C1>::pointer;
using P2 = typename impl_ptr<T2, D2, C2>::pointer;
using CT = typename std::common_type<P1, P2>::type;
return std::less<CT>()(l.get(), r.get());
}
template <class T1, class D1, class C1, class T2, class D2, class C2>
inline bool operator> (const impl_ptr<T1, D1, C1>& l, const impl_ptr<T2, D2, C2>& r)
{
return r < l;
}
template <class T1, class D1, class C1, class T2, class D2, class C2>
inline bool operator<=(const impl_ptr<T1, D1, C1>& l, const impl_ptr<T2, D2, C2>& r)
{
return !(r < l);
}
template <class T1, class D1, class C1, class T2, class D2, class C2>
inline bool operator>=(const impl_ptr<T1, D1, C1>& l, const impl_ptr<T2, D2, C2>& r)
{
return !(l < r);
}
template <class T, class D, class C>
inline bool operator==(const impl_ptr<T, D, C>& p, std::nullptr_t) SPIMPL_NOEXCEPT
{
return !p;
}
template <class T, class D, class C>
inline bool operator==(std::nullptr_t, const impl_ptr<T, D, C>& p) SPIMPL_NOEXCEPT
{
return !p;
}
template <class T, class D, class C>
inline bool operator!=(const impl_ptr<T, D, C>& p, std::nullptr_t) SPIMPL_NOEXCEPT
{
return static_cast<bool>(p);
}
template <class T, class D, class C>
inline bool operator!=(std::nullptr_t, const impl_ptr<T, D, C>& p) SPIMPL_NOEXCEPT
{
return static_cast<bool>(p);
}
template <class T, class D, class C>
inline bool operator< (const impl_ptr<T, D, C>& l, std::nullptr_t)
{
using P = typename impl_ptr<T, D, C>::pointer;
return std::less<P>()(l.get(), nullptr);
}
template <class T, class D, class C>
inline bool operator< (std::nullptr_t, const impl_ptr<T, D, C>& p)
{
using P = typename impl_ptr<T, D, C>::pointer;
return std::less<P>()(nullptr, p.get());
}
template <class T, class D, class C>
inline bool operator> (const impl_ptr<T, D, C>& p, std::nullptr_t)
{
return nullptr < p;
}
template <class T, class D, class C>
inline bool operator> (std::nullptr_t, const impl_ptr<T, D, C>& p)
{
return p < nullptr;
}
template <class T, class D, class C>
inline bool operator<=(const impl_ptr<T, D, C>& p, std::nullptr_t)
{
return !(nullptr < p);
}
template <class T, class D, class C>
inline bool operator<=(std::nullptr_t, const impl_ptr<T, D, C>& p)
{
return !(p < nullptr);
}
template <class T, class D, class C>
inline bool operator>=(const impl_ptr<T, D, C>& p, std::nullptr_t)
{
return !(p < nullptr);
}
template <class T, class D, class C>
inline bool operator>=(std::nullptr_t, const impl_ptr<T, D, C>& p)
{
return !(nullptr < p);
}
template<class T, class... Args>
inline impl_ptr<T> make_impl(Args&&... args)
{
return impl_ptr<T>(new T(std::forward<Args>(args)...), &details::default_delete<T>, &details::default_copy<T>);
}
// Helpers to manage unique impl, stored in std::unique_ptr
template<class T, class Deleter = void(*)(T*)>
using unique_impl_ptr = std::unique_ptr<T, Deleter>;
template<class T, class... Args>
inline unique_impl_ptr<T> make_unique_impl(Args&&... args)
{
static_assert(!std::is_array<T>::value, "unique_impl_ptr does not support arrays");
return unique_impl_ptr<T>(new T(std::forward<Args>(args)...), &details::default_delete<T>);
}
}
namespace std {
template <class T, class D, class C>
struct hash<spimpl::impl_ptr<T, D, C>>
{
using argument_type = spimpl::impl_ptr<T, D, C> ;
using result_type = size_t;
result_type operator()(const argument_type& p) const SPIMPL_NOEXCEPT
{
return hash<typename argument_type::pointer>()(p.get());
}
};
}
#endif // SPIMPL_H_