tornavis/source/blender/blenlib/BLI_listbase_wrapper.hh

99 lines
2.1 KiB
C++

/* SPDX-License-Identifier: GPL-2.0-or-later */
#pragma once
/** \file
* \ingroup bli
*
* `blender::ListBaseWrapper` is a typed wrapper for the #ListBase struct. That makes it safer and
* more convenient to use in C++ in some cases. However, if you find yourself iterating over a
* linked list a lot, consider to convert it into a vector for further processing. This improves
* performance and debug-ability.
*/
#include "BLI_listbase.h"
#include "DNA_listBase.h"
namespace blender {
template<typename LB, typename T> class ListBaseWrapperTemplate {
private:
LB *listbase_;
public:
ListBaseWrapperTemplate(LB *listbase) : listbase_(listbase)
{
BLI_assert(listbase);
}
ListBaseWrapperTemplate(LB &listbase) : ListBaseWrapperTemplate(&listbase) {}
class Iterator {
private:
LB *listbase_;
T *current_;
public:
Iterator(LB *listbase, T *current) : listbase_(listbase), current_(current) {}
Iterator &operator++()
{
/* Some types store `next/prev` using `void *`, so cast is necessary. */
current_ = static_cast<T *>(current_->next);
return *this;
}
Iterator operator++(int)
{
Iterator iterator = *this;
++(*this);
return iterator;
}
bool operator!=(const Iterator &iterator) const
{
return current_ != iterator.current_;
}
T *operator*() const
{
return current_;
}
};
Iterator begin() const
{
return Iterator(listbase_, static_cast<T *>(listbase_->first));
}
Iterator end() const
{
return Iterator(listbase_, nullptr);
}
T *get(uint index) const
{
void *ptr = BLI_findlink(listbase_, index);
BLI_assert(ptr);
return static_cast<T *>(ptr);
}
int64_t index_of(const T *value) const
{
int64_t index = 0;
for (T *ptr : *this) {
if (ptr == value) {
return index;
}
index++;
}
BLI_assert(false);
return -1;
}
};
template<typename T> using ListBaseWrapper = ListBaseWrapperTemplate<ListBase, T>;
template<typename T> using ConstListBaseWrapper = ListBaseWrapperTemplate<const ListBase, const T>;
} /* namespace blender */