skia2/include/private/SkUniquePtr.h
bungeman 1fce5584cf Work around vs2013sp2-3 bug in skstd::unique_ptr.
When compiling skstd::unique_ptr::compressed_base with the vc++ in
some intermediate service pack versions of Visual Studio 2013 the
compiler will crash with an internal compiler error. In the interest of
reducing headaches, work around this issue in skstd::unique_ptr until
std::unique_ptr can be used.

BUG=skia:4564

Review URL: https://codereview.chromium.org/1636503002
2016-01-25 13:00:34 -08:00

409 lines
14 KiB
C++

/*
* Copyright 2015 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkUniquePtr_DEFINED
#define SkUniquePtr_DEFINED
#include "SkTLogic.h"
#include <cstddef>
#include <utility>
namespace skstd {
template <typename T> struct default_delete {
/*constexpr*/ default_delete() /*noexcept*/ = default;
template <typename U, typename = enable_if_t<is_convertible<U*, T*>::value>>
default_delete(const default_delete<U>&) /*noexcept*/ {}
void operator()(T* obj) const {
static_assert(sizeof(T) > 0, "Deleting pointer to incomplete type!");
delete obj;
}
};
template <typename T> struct default_delete<T[]> {
/*constexpr*/ default_delete() /*noexcept*/ = default;
void operator()(T* obj) const {
static_assert(sizeof(T) > 0, "Deleting pointer to incomplete type!");
delete [] obj;
}
};
template <typename T, typename D = default_delete<T>> class unique_ptr {
// remove_reference_t<D>::pointer if that type exists, otherwise T*.
struct pointer_type_detector {
template <typename U> static typename U::pointer detector(typename U::pointer*);
template <typename U> static T* detector(...);
using type = decltype(detector<remove_reference_t<D>>(0));
};
public:
using pointer = typename pointer_type_detector::type;
using element_type = T;
using deleter_type = D;
private:
template <typename B, bool>
struct compressed_base : private B {
/*constexpr*/ compressed_base() : B() {}
/*constexpr*/ compressed_base(const B& b) : B(b) {}
/*constexpr*/ compressed_base(B&& b) : B(std::move(b)) {}
/*constexpr*/ B& get() /*noexcept*/ { return *this; }
/*constexpr*/ B const& get() const /*noexcept*/ { return *this; }
void swap(compressed_base&) /*noexcept*/ { }
};
template <typename B> struct compressed_base<B, false> {
B fb;
/*constexpr*/ compressed_base() : B() {}
/*constexpr*/ compressed_base(const B& b) : fb(b) {}
/*constexpr*/ compressed_base(B&& b) : fb(std::move(b)) {}
/*constexpr*/ B& get() /*noexcept*/ { return fb; }
/*constexpr*/ B const& get() const /*noexcept*/ { return fb; }
void swap(compressed_base& that) /*noexcept*/ { SkTSwap(fb, that.fB); }
};
// C++14 adds '&& !std::is_final<deleter_type>::value' to the bool condition.
// compressed_base_t exists and has this form to work around a bug in vs2013sp2-3
using compressed_base_t = compressed_base<deleter_type, std::is_empty<deleter_type>::value>;
struct compressed_data : private compressed_base_t {
pointer fPtr;
/*constexpr*/ compressed_data() : compressed_base_t(), fPtr() {}
/*constexpr*/ compressed_data(const pointer& ptr, const deleter_type& d)
: compressed_base_t(d), fPtr(ptr) {}
template <typename U1, typename U2, typename = enable_if_t<
is_convertible<U1, pointer>::value && is_convertible<U2, deleter_type>::value
>> /*constexpr*/ compressed_data(U1&& ptr, U2&& d)
: compressed_base_t(std::forward<U2>(d)), fPtr(std::forward<U1>(ptr)) {}
/*constexpr*/ pointer& getPointer() /*noexcept*/ { return fPtr; }
/*constexpr*/ pointer const& getPointer() const /*noexcept*/ { return fPtr; }
/*constexpr*/ deleter_type& getDeleter() /*noexcept*/ {
return compressed_base_t::get();
}
/*constexpr*/ deleter_type const& getDeleter() const /*noexcept*/ {
return compressed_base_t::get();
}
void swap(compressed_data& that) /*noexcept*/ {
compressed_base_t::swap(static_cast<compressed_base_t>(that));
SkTSwap(fPtr, that.fPtr);
}
};
compressed_data data;
public:
/*constexpr*/ unique_ptr() /*noexcept*/ : data() {
static_assert(!std::is_pointer<deleter_type>::value, "Deleter nullptr function pointer!");
}
/*constexpr*/ unique_ptr(std::nullptr_t) /*noexcept*/ : unique_ptr() { }
explicit unique_ptr(pointer ptr) /*noexcept*/ : data(ptr, deleter_type()) {
static_assert(!std::is_pointer<deleter_type>::value, "Deleter nullptr function pointer!");
}
unique_ptr(pointer ptr,
conditional_t<std::is_reference<deleter_type>::value,
deleter_type, const deleter_type&> d)
/*noexcept*/ : data(ptr, d)
{}
unique_ptr(pointer ptr, remove_reference_t<deleter_type>&& d) /*noexcept*/
: data(std::move(ptr), std::move(d))
{
static_assert(!std::is_reference<deleter_type>::value,
"Binding an rvalue reference deleter as an lvalue reference deleter is not allowed.");
}
unique_ptr(unique_ptr&& that) /*noexcept*/
: data(that.release(), std::forward<deleter_type>(that.get_deleter()))
{}
template <typename U, typename ThatD, typename = enable_if_t<
is_convertible<typename unique_ptr<U, ThatD>::pointer, pointer>::value &&
!std::is_array<U>::value &&
conditional_t<std::is_reference<D>::value,
std::is_same<ThatD, D>,
is_convertible<ThatD, D>>::value>>
unique_ptr(unique_ptr<U, ThatD>&& that) /*noexcept*/
: data(that.release(), std::forward<ThatD>(that.get_deleter()))
{}
~unique_ptr() /*noexcept*/ {
pointer& ptr = data.getPointer();
if (ptr != nullptr) {
get_deleter()(ptr);
}
ptr = pointer();
}
unique_ptr& operator=(unique_ptr&& that) /*noexcept*/ {
reset(that.release());
get_deleter() = std::forward<deleter_type>(that.get_deleter());
return *this;
}
template <typename U, typename ThatD> enable_if_t<
is_convertible<typename unique_ptr<U, ThatD>::pointer, pointer>::value &&
!std::is_array<U>::value,
unique_ptr&> operator=(unique_ptr<U, ThatD>&& that) /*noexcept*/ {
reset(that.release());
get_deleter() = std::forward<ThatD>(that.get_deleter());
return *this;
}
unique_ptr& operator=(std::nullptr_t) /*noexcept*/ {
reset();
return *this;
}
add_lvalue_reference_t<element_type> operator*() const {
SkASSERT(get() != pointer());
return *get();
}
pointer operator->() const /*noexcept*/ {
SkASSERT(get() != pointer());
return get();
}
pointer get() const /*noexcept*/ {
return data.getPointer();
}
deleter_type& get_deleter() /*noexcept*/ {
return data.getDeleter();
}
const deleter_type& get_deleter() const /*noexcept*/ {
return data.getDeleter();
}
//explicit operator bool() const noexcept {
bool is_attached() const /*noexcept*/ {
return get() == pointer() ? false : true;
}
pointer release() /*noexcept*/ {
pointer ptr = get();
data.getPointer() = pointer();
return ptr;
}
void reset(pointer ptr = pointer()) /*noexcept*/ {
SkTSwap(data.getPointer(), ptr);
if (ptr != pointer()) {
get_deleter()(ptr);
}
}
void swap(unique_ptr& that) /*noexcept*/ {
SkTSwap(data, that.data);
}
unique_ptr(const unique_ptr&) = delete;
unique_ptr& operator=(const unique_ptr&) = delete;
};
template <typename T, typename D> class unique_ptr<T[], D> {
// remove_reference_t<D>::pointer if that type exists, otherwise T*.
struct pointer_type_detector {
template <typename U> static typename U::pointer detector(typename U::pointer*);
template <typename U> static T* detector(...);
using type = decltype(detector<remove_reference_t<D>>(0));
};
public:
using pointer = typename pointer_type_detector::type;
using element_type = T;
using deleter_type = D;
private:
template <typename B, bool> struct compressed_base : private B {
/*constexpr*/ compressed_base() : B() {}
/*constexpr*/ compressed_base(const B& b) : B(b) {}
/*constexpr*/ compressed_base(B&& b) : B(std::move(b)) {}
/*constexpr*/ B& get() /*noexcept*/ { return *this; }
/*constexpr*/ B const& get() const /*noexcept*/ { return *this; }
void swap(compressed_base&) /*noexcept*/ { }
};
template <typename B> struct compressed_base<B, false> {
B fb;
/*constexpr*/ compressed_base() : B() {}
/*constexpr*/ compressed_base(const B& b) : fb(b) {}
/*constexpr*/ compressed_base(B&& b) : fb(std::move(b)) {}
/*constexpr*/ B& get() /*noexcept*/ { return fb; }
/*constexpr*/ B const& get() const /*noexcept*/ { return fb; }
void swap(compressed_base& that) /*noexcept*/ { SkTSwap(fb, that.fB); }
};
// C++14 adds '&& !std::is_final<deleter_type>::value' to the bool condition.
// compressed_base_t exists and has this form to work around a bug in vs2013sp2-3
using compressed_base_t = compressed_base<deleter_type, std::is_empty<deleter_type>::value>;
struct compressed_data : private compressed_base_t {
pointer fPtr;
/*constexpr*/ compressed_data() : compressed_base_t(), fPtr() {}
/*constexpr*/ compressed_data(const pointer& ptr, const deleter_type& d)
: compressed_base_t(d), fPtr(ptr) {}
template <typename U1, typename U2, typename = enable_if_t<
is_convertible<U1, pointer>::value && is_convertible<U2, deleter_type>::value
>> /*constexpr*/ compressed_data(U1&& ptr, U2&& d)
: compressed_base_t(std::forward<U2>(d)), fPtr(std::forward<U1>(ptr)) {}
/*constexpr*/ pointer& getPointer() /*noexcept*/ { return fPtr; }
/*constexpr*/ pointer const& getPointer() const /*noexcept*/ { return fPtr; }
/*constexpr*/ deleter_type& getDeleter() /*noexcept*/ {
return compressed_base_t::get();
}
/*constexpr*/ deleter_type const& getDeleter() const /*noexcept*/ {
return compressed_base_t::get();
}
void swap(compressed_data& that) /*noexcept*/ {
compressed_base_t::swap(static_cast<compressed_base_t>(that));
SkTSwap(fPtr, that.fPtr);
}
};
compressed_data data;
public:
/*constexpr*/ unique_ptr() /*noexcept*/ : data() {
static_assert(!std::is_pointer<deleter_type>::value, "Deleter nullptr function pointer!");
}
/*constexpr*/ unique_ptr(std::nullptr_t) /*noexcept*/ : unique_ptr() { }
explicit unique_ptr(pointer ptr) /*noexcept*/ : data(ptr, deleter_type()) {
static_assert(!std::is_pointer<deleter_type>::value, "Deleter nullptr function pointer!");
}
unique_ptr(pointer ptr,
conditional_t<std::is_reference<deleter_type>::value,
deleter_type, const deleter_type&> d)
/*noexcept*/ : data(ptr, d)
{}
unique_ptr(pointer ptr, remove_reference_t<deleter_type>&& d) /*noexcept*/
: data(std::move(ptr), std::move(d))
{
static_assert(!std::is_reference<deleter_type>::value,
"Binding an rvalue reference deleter as an lvalue reference deleter is not allowed.");
}
unique_ptr(unique_ptr&& that) /*noexcept*/
: data(that.release(), std::forward<deleter_type>(that.get_deleter()))
{}
~unique_ptr() {
pointer& ptr = data.getPointer();
if (ptr != nullptr) {
get_deleter()(ptr);
}
ptr = pointer();
}
unique_ptr& operator=(unique_ptr&& that) /*noexcept*/ {
reset(that.release());
get_deleter() = std::forward<deleter_type>(that.get_deleter());
return *this;
}
unique_ptr& operator=(std::nullptr_t) /*noexcept*/ {
reset();
return *this;
}
add_lvalue_reference_t<element_type> operator[](size_t i) const {
SkASSERT(get() != pointer());
return get()[i];
}
pointer get() const /*noexcept*/ {
return data.getPointer();
}
deleter_type& get_deleter() /*noexcept*/ {
return data.getDeleter();
}
const deleter_type& get_deleter() const /*noexcept*/ {
return data.getDeleter();
}
//explicit operator bool() const noexcept {
bool is_attached() const /*noexcept*/ {
return get() == pointer() ? false : true;
}
pointer release() /*noexcept*/ {
pointer ptr = get();
data.getPointer() = pointer();
return ptr;
}
void reset(pointer ptr = pointer()) /*noexcept*/ {
SkTSwap(data.getPointer(), ptr);
if (ptr != pointer()) {
get_deleter()(ptr);
}
}
template <typename U> void reset(U*) = delete;
void swap(unique_ptr& that) /*noexcept*/ {
data.swap(that.data);
}
unique_ptr(const unique_ptr&) = delete;
unique_ptr& operator=(const unique_ptr&) = delete;
};
template <typename T, typename D>
inline void swap(unique_ptr<T, D>& a, unique_ptr<T, D>& b) /*noexcept*/ {
a.swap(b);
}
template <typename T, typename D, typename U, typename ThatD>
inline bool operator==(const unique_ptr<T, D>& a, const unique_ptr<U, ThatD>& b) {
return a.get() == b.get();
}
template <typename T, typename D>
inline bool operator==(const unique_ptr<T, D>& a, std::nullptr_t) /*noexcept*/ {
//return !a;
return !a.is_attached();
}
template <typename T, typename D>
inline bool operator==(std::nullptr_t, const unique_ptr<T, D>& b) /*noexcept*/ {
//return !b;
return !b.is_attached();
}
template <typename T, typename D, typename U, typename ThatD>
inline bool operator!=(const unique_ptr<T, D>& a, const unique_ptr<U, ThatD>& b) {
return a.get() != b.get();
}
template <typename T, typename D>
inline bool operator!=(const unique_ptr<T, D>& a, std::nullptr_t) /*noexcept*/ {
//return (bool)a;
return a.is_attached();
}
template <typename T, typename D>
inline bool operator!=(std::nullptr_t, const unique_ptr<T, D>& b) /*noexcept*/ {
//return (bool)b;
return b.is_attached();
}
} // namespace skstd
#endif