/*
* Copyright 2017 Google LLC
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkArenaAllocList_DEFINED
#define SkArenaAllocList_DEFINED
#include "include/private/base/SkAssert.h"
#include "src/base/SkArenaAlloc.h" // IWYU pragma: keep
#include <utility>
/**
* A singly linked list of Ts stored in a SkArenaAlloc. The arena rather than the list owns
* the elements. This supports forward iteration and range based for loops.
*/
template <typename T>
class SkArenaAllocList {
private:
struct Node;
public:
SkArenaAllocList() = default;
void
reset() { fHead = fTail = nullptr; }
template <typename... Args>
inline T& append(SkArenaAlloc* arena, Args... args);
class Iter {
public:
Iter() = default;
inline Iter& operator++();
T& operator*() const {
return fCurr->fT; }
T* operator->() const {
return &fCurr->fT; }
bool operator==(const Iter& that) const {
return fCurr == that.fCurr; }
bool operator!=(const Iter& that) const {
return !(*this == that); }
private:
friend
class SkArenaAllocList;
explicit Iter(Node* node) : fCurr(node) {}
Node* fCurr = nullptr;
};
Iter begin() {
return Iter(fHead); }
Iter
end() {
return Iter(); }
Iter tail() {
return Iter(fTail); }
private:
struct Node {
template <typename... Args>
Node(Args... args) : fT(std::forward<Args>(args)...) {}
T fT;
Node* fNext = nullptr;
};
Node* fHead = nullptr;
Node* fTail = nullptr;
};
template <typename T>
template <typename... Args>
T& SkArenaAllocList<T>::append(SkArenaAlloc* arena, Args... args) {
SkASSERT(!fHead == !fTail);
auto* n = arena->make<Node>(std::forward<Args>(args)...);
if (!fTail) {
fHead = fTail = n;
}
else {
fTail = fTail->fNext = n;
}
return fTail->fT;
}
template <typename T>
typename SkArenaAllocList<T>::Iter& SkArenaAllocList<T>::Iter::operator++() {
fCurr = fCurr->fNext;
return *this;
}
#endif
