[vector] Allow to iterate with mutables (#7586)
Co-authored-by: ArnaudD-FR <arnaud.desmier@gmail.com>
Co-authored-by: Derek Bailey <derekbailey@google.com>
diff --git a/include/flatbuffers/array.h b/include/flatbuffers/array.h
index d4b73fc..ec34dee 100644
--- a/include/flatbuffers/array.h
+++ b/include/flatbuffers/array.h
@@ -35,7 +35,7 @@
public:
typedef uint16_t size_type;
typedef typename IndirectHelper<IndirectHelperType>::return_type return_type;
- typedef VectorIterator<T, return_type> const_iterator;
+ typedef VectorConstIterator<T, return_type> const_iterator;
typedef VectorReverseIterator<const_iterator> const_reverse_iterator;
// If T is a LE-scalar or a struct (!scalar_tag::value).
diff --git a/include/flatbuffers/buffer.h b/include/flatbuffers/buffer.h
index ca005f7..96ae538 100644
--- a/include/flatbuffers/buffer.h
+++ b/include/flatbuffers/buffer.h
@@ -76,6 +76,9 @@
static return_type Read(const uint8_t *p, uoffset_t i) {
return EndianScalar((reinterpret_cast<const T *>(p))[i]);
}
+ static return_type Read(uint8_t *p, uoffset_t i) {
+ return Read(const_cast<const uint8_t *>(p), i);
+ }
};
template<typename T> struct IndirectHelper<Offset<T>> {
typedef const T *return_type;
@@ -85,13 +88,20 @@
p += i * sizeof(uoffset_t);
return reinterpret_cast<return_type>(p + ReadScalar<uoffset_t>(p));
}
+ static mutable_return_type Read(uint8_t *p, uoffset_t i) {
+ p += i * sizeof(uoffset_t);
+ return reinterpret_cast<mutable_return_type>(p + ReadScalar<uoffset_t>(p));
+ }
};
template<typename T> struct IndirectHelper<const T *> {
typedef const T *return_type;
typedef T *mutable_return_type;
static const size_t element_stride = sizeof(T);
static return_type Read(const uint8_t *p, uoffset_t i) {
- return reinterpret_cast<const T *>(p + i * sizeof(T));
+ return reinterpret_cast<return_type>(p + i * sizeof(T));
+ }
+ static mutable_return_type Read(uint8_t *p, uoffset_t i) {
+ return reinterpret_cast<mutable_return_type>(p + i * sizeof(T));
}
};
diff --git a/include/flatbuffers/vector.h b/include/flatbuffers/vector.h
index 6bcdfe2..9cb6a2d 100644
--- a/include/flatbuffers/vector.h
+++ b/include/flatbuffers/vector.h
@@ -27,14 +27,15 @@
// An STL compatible iterator implementation for Vector below, effectively
// calling Get() for every element.
-template<typename T, typename IT> struct VectorIterator {
+template<typename T, typename IT, typename Data = uint8_t *>
+struct VectorIterator {
typedef std::random_access_iterator_tag iterator_category;
typedef IT value_type;
typedef ptrdiff_t difference_type;
typedef IT *pointer;
typedef IT &reference;
- VectorIterator(const uint8_t *data, uoffset_t i)
+ VectorIterator(Data data, uoffset_t i)
: data_(data + IndirectHelper<T>::element_stride * i) {}
VectorIterator(const VectorIterator &other) : data_(other.data_) {}
VectorIterator() : data_(nullptr) {}
@@ -116,9 +117,12 @@
}
private:
- const uint8_t *data_;
+ Data data_;
};
+template<typename T, typename IT>
+using VectorConstIterator = VectorIterator<T, IT, const uint8_t *>;
+
template<typename Iterator>
struct VectorReverseIterator : public std::reverse_iterator<Iterator> {
explicit VectorReverseIterator(Iterator iter)
@@ -145,7 +149,7 @@
public:
typedef VectorIterator<T, typename IndirectHelper<T>::mutable_return_type>
iterator;
- typedef VectorIterator<T, typename IndirectHelper<T>::return_type>
+ typedef VectorConstIterator<T, typename IndirectHelper<T>::return_type>
const_iterator;
typedef VectorReverseIterator<iterator> reverse_iterator;
typedef VectorReverseIterator<const_iterator> const_reverse_iterator;
diff --git a/tests/monster_test.cpp b/tests/monster_test.cpp
index 4fc9e14..6e810dd 100644
--- a/tests/monster_test.cpp
+++ b/tests/monster_test.cpp
@@ -439,6 +439,16 @@
TEST_EQ(first->hp(), 0);
first->mutate_hp(1000);
+ // Test for each loop over mutable entries
+ for (auto item: *tables)
+ {
+ TEST_EQ(item->hp(), 1000);
+ item->mutate_hp(0);
+ TEST_EQ(item->hp(), 0);
+ item->mutate_hp(1000);
+ break; // one iteration is enough, just testing compilation
+ }
+
// Mutate via LookupByKey
TEST_NOTNULL(tables->MutableLookupByKey("Barney"));
TEST_EQ(static_cast<Monster *>(nullptr),
