[Bf-blender-cvs] [e7274f9f2d4] master: BLI: add a common base class for Map iterators
Jacques Lucke
noreply at git.blender.org
Fri Apr 30 16:29:31 CEST 2021
Commit: e7274f9f2d4191b3b1b77448e2c1ea6f1f4aa97c
Author: Jacques Lucke
Date: Fri Apr 30 16:17:16 2021 +0200
Branches: master
https://developer.blender.org/rBe7274f9f2d4191b3b1b77448e2c1ea6f1f4aa97c
BLI: add a common base class for Map iterators
This is useful for an upcoming commit that allows removing
an element based on an iterator.
===================================================================
M source/blender/blenlib/BLI_map.hh
===================================================================
diff --git a/source/blender/blenlib/BLI_map.hh b/source/blender/blenlib/BLI_map.hh
index 376bf5df06f..c69d5986885 100644
--- a/source/blender/blenlib/BLI_map.hh
+++ b/source/blender/blenlib/BLI_map.hh
@@ -621,19 +621,23 @@ class Map {
}
}
- /**
- * A utility iterator that reduces the amount of code when implementing the actual iterators.
- * This uses the "curiously recurring template pattern" (CRTP).
- */
- template<typename SubIterator> struct BaseIterator {
+ /* Common base class for all iterators below. */
+ struct BaseIterator {
+ public:
using iterator_category = std::forward_iterator_tag;
using difference_type = std::ptrdiff_t;
+ protected:
+ /* We could have separate base iterators for const and non-const iterators, but that would add
+ * more complexity than benefits right now. */
Slot *slots_;
int64_t total_slots_;
int64_t current_slot_;
- BaseIterator(const Slot *slots, int64_t total_slots, int64_t current_slot)
+ friend Map;
+
+ public:
+ BaseIterator(const Slot *slots, const int64_t total_slots, const int64_t current_slot)
: slots_(const_cast<Slot *>(slots)), total_slots_(total_slots), current_slot_(current_slot)
{
}
@@ -667,11 +671,29 @@ class Map {
return !(a != b);
}
+ protected:
+ Slot ¤t_slot() const
+ {
+ return slots_[current_slot_];
+ }
+ };
+
+ /**
+ * A utility iterator that reduces the amount of code when implementing the actual iterators.
+ * This uses the "curiously recurring template pattern" (CRTP).
+ */
+ template<typename SubIterator> class BaseIteratorRange : public BaseIterator {
+ public:
+ BaseIteratorRange(const Slot *slots, int64_t total_slots, int64_t current_slot)
+ : BaseIterator(slots, total_slots, current_slot)
+ {
+ }
+
SubIterator begin() const
{
- for (int64_t i = 0; i < total_slots_; i++) {
- if (slots_[i].is_occupied()) {
- return SubIterator(slots_, total_slots_, i);
+ for (int64_t i = 0; i < this->total_slots_; i++) {
+ if (this->slots_[i].is_occupied()) {
+ return SubIterator(this->slots_, this->total_slots_, i);
}
}
return this->end();
@@ -679,23 +701,18 @@ class Map {
SubIterator end() const
{
- return SubIterator(slots_, total_slots_, total_slots_);
- }
-
- Slot ¤t_slot() const
- {
- return slots_[current_slot_];
+ return SubIterator(this->slots_, this->total_slots_, this->total_slots_);
}
};
- class KeyIterator final : public BaseIterator<KeyIterator> {
+ class KeyIterator final : public BaseIteratorRange<KeyIterator> {
public:
using value_type = Key;
using pointer = const Key *;
using reference = const Key &;
KeyIterator(const Slot *slots, int64_t total_slots, int64_t current_slot)
- : BaseIterator<KeyIterator>(slots, total_slots, current_slot)
+ : BaseIteratorRange<KeyIterator>(slots, total_slots, current_slot)
{
}
@@ -705,14 +722,14 @@ class Map {
}
};
- class ValueIterator final : public BaseIterator<ValueIterator> {
+ class ValueIterator final : public BaseIteratorRange<ValueIterator> {
public:
using value_type = Value;
using pointer = const Value *;
using reference = const Value &;
ValueIterator(const Slot *slots, int64_t total_slots, int64_t current_slot)
- : BaseIterator<ValueIterator>(slots, total_slots, current_slot)
+ : BaseIteratorRange<ValueIterator>(slots, total_slots, current_slot)
{
}
@@ -722,14 +739,14 @@ class Map {
}
};
- class MutableValueIterator final : public BaseIterator<MutableValueIterator> {
+ class MutableValueIterator final : public BaseIteratorRange<MutableValueIterator> {
public:
using value_type = Value;
using pointer = Value *;
using reference = Value &;
- MutableValueIterator(const Slot *slots, int64_t total_slots, int64_t current_slot)
- : BaseIterator<MutableValueIterator>(slots, total_slots, current_slot)
+ MutableValueIterator(Slot *slots, int64_t total_slots, int64_t current_slot)
+ : BaseIteratorRange<MutableValueIterator>(slots, total_slots, current_slot)
{
}
@@ -754,14 +771,14 @@ class Map {
}
};
- class ItemIterator final : public BaseIterator<ItemIterator> {
+ class ItemIterator final : public BaseIteratorRange<ItemIterator> {
public:
using value_type = Item;
using pointer = Item *;
using reference = Item &;
ItemIterator(const Slot *slots, int64_t total_slots, int64_t current_slot)
- : BaseIterator<ItemIterator>(slots, total_slots, current_slot)
+ : BaseIteratorRange<ItemIterator>(slots, total_slots, current_slot)
{
}
@@ -772,14 +789,14 @@ class Map {
}
};
- class MutableItemIterator final : public BaseIterator<MutableItemIterator> {
+ class MutableItemIterator final : public BaseIteratorRange<MutableItemIterator> {
public:
using value_type = MutableItem;
using pointer = MutableItem *;
using reference = MutableItem &;
- MutableItemIterator(const Slot *slots, int64_t total_slots, int64_t current_slot)
- : BaseIterator<MutableItemIterator>(slots, total_slots, current_slot)
+ MutableItemIterator(Slot *slots, int64_t total_slots, int64_t current_slot)
+ : BaseIteratorRange<MutableItemIterator>(slots, total_slots, current_slot)
{
}
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