BigfootDev/flatbuffers
1
0
Fork 1
mirror of https://github.com/google/flatbuffers.git synced 2026-06-24 19:16:09 +00:00
Code Issues Packages Projects Releases Wiki Activity

[C++] add make_span for Array<T,N> (#6663)

Browse Source 
* [C++] Add make_span for Array<T,N> and Vector<T>

* [C++] Add tests for make_span<T,N>(Array<T,N>)

* [C++] Add span iterators

* [C++] Checked span iterator (MSVC)

* Fix review notes
This commit is contained in:
Vladimir Glavnyy
2021-06-29 00:22:02 +07:00
committed by GitHub
parent bd37e67ac0
commit 22498cf3a9
3 changed files with 257 additions and 66 deletions
Download Patch File Download Diff File Expand all files Collapse all files

120
include/flatbuffers/stl_emulation.h
View File

@@ -166,6 +166,8 @@ inline void vector_emplace_back(std::vector<T> *vector, V &&data) {
using integral_constant = std::integral_constant<T, v>;
template <bool B>
using bool_constant = integral_constant<bool, B>;
using true_type = std::true_type;
using false_type = std::false_type;
#else
// Map C++ TR1 templates defined by stlport.
template <typename T> using is_scalar = std::tr1::is_scalar<T>;
@@ -191,6 +193,8 @@ inline void vector_emplace_back(std::vector<T> *vector, V &&data) {
using integral_constant = std::tr1::integral_constant<T, v>;
template <bool B>
using bool_constant = integral_constant<bool, B>;
using true_type = bool_constant<true>;
using false_type = bool_constant<false>;
#endif // !FLATBUFFERS_CPP98_STL
#else
// MSVC 2010 doesn't support C++11 aliases.
@@ -207,6 +211,8 @@ inline void vector_emplace_back(std::vector<T> *vector, V &&data) {
struct integral_constant : public std::integral_constant<T, v> {};
template <bool B>
struct bool_constant : public integral_constant<bool, B> {};
typedef bool_constant<true> true_type;
typedef bool_constant<false> false_type;
#endif // defined(FLATBUFFERS_TEMPLATES_ALIASES)
#ifndef FLATBUFFERS_CPP98_STL
@@ -495,6 +501,32 @@ namespace internal {
int, void>::type;
};
template<typename T>
struct SpanIterator {
// TODO: upgrade to std::random_access_iterator_tag.
using iterator_category = std::forward_iterator_tag;
using difference_type = std::ptrdiff_t;
using value_type = typename std::remove_cv<T>::type;
using reference = T&;
using pointer = T*;
// Convince MSVC compiler that this iterator is trusted (it is verified).
#ifdef _MSC_VER
using _Unchecked_type = pointer;
#endif // _MSC_VER
SpanIterator(pointer ptr) : ptr_(ptr) {}
reference operator*() const { return *ptr_; }
pointer operator->() { return ptr_; }
SpanIterator& operator++() { ptr_++; return *this; }
SpanIterator operator++(int) { auto tmp = *this; ++(*this); return tmp; }
friend bool operator== (const SpanIterator& lhs, const SpanIterator& rhs) { return lhs.ptr_ == rhs.ptr_; }
friend bool operator!= (const SpanIterator& lhs, const SpanIterator& rhs) { return lhs.ptr_ != rhs.ptr_; }
private:
pointer ptr_;
};
} // namespace internal
#endif // !defined(FLATBUFFERS_SPAN_MINIMAL)
@@ -534,6 +566,17 @@ class span FLATBUFFERS_FINAL_CLASS {
return data_;
}
#if !defined(FLATBUFFERS_SPAN_MINIMAL)
using Iterator = internal::SpanIterator<T>;
using ConstIterator = internal::SpanIterator<const T>;
Iterator begin() const { return Iterator(data()); }
Iterator end() const { return Iterator(data() + size()); }
ConstIterator cbegin() const { return ConstIterator(data()); }
ConstIterator cend() const { return ConstIterator(data() + size()); }
#endif
// Returns a reference to the idx-th element of the sequence.
// The behavior is undefined if the idx is greater than or equal to size().
FLATBUFFERS_CONSTEXPR_CPP11 reference operator[](size_type idx) const {
@@ -627,47 +670,46 @@ class span FLATBUFFERS_FINAL_CLASS {
pointer const data_;
const size_type count_;
};
#if !defined(FLATBUFFERS_SPAN_MINIMAL)
template<class U, std::size_t N>
FLATBUFFERS_CONSTEXPR_CPP11
flatbuffers::span<U, N> make_span(U(&arr)[N]) FLATBUFFERS_NOEXCEPT {
return span<U, N>(arr);
}
template<class U, std::size_t N>
FLATBUFFERS_CONSTEXPR_CPP11
flatbuffers::span<const U, N> make_span(const U(&arr)[N]) FLATBUFFERS_NOEXCEPT {
return span<const U, N>(arr);
}
template<class U, std::size_t N>
FLATBUFFERS_CONSTEXPR_CPP11
flatbuffers::span<U, N> make_span(std::array<U, N> &arr) FLATBUFFERS_NOEXCEPT {
return span<U, N>(arr);
}
template<class U, std::size_t N>
FLATBUFFERS_CONSTEXPR_CPP11
flatbuffers::span<const U, N> make_span(const std::array<U, N> &arr) FLATBUFFERS_NOEXCEPT {
return span<const U, N>(arr);
}
template<class U, std::size_t N>
FLATBUFFERS_CONSTEXPR_CPP11
flatbuffers::span<U, dynamic_extent> make_span(U *first, std::size_t count) FLATBUFFERS_NOEXCEPT {
return span<U, dynamic_extent>(first, count);
}
template<class U, std::size_t N>
FLATBUFFERS_CONSTEXPR_CPP11
flatbuffers::span<const U, dynamic_extent> make_span(const U *first, std::size_t count) FLATBUFFERS_NOEXCEPT {
return span<const U, dynamic_extent>(first, count);
}
#endif
#endif // defined(FLATBUFFERS_USE_STD_SPAN)
#if !defined(FLATBUFFERS_SPAN_MINIMAL)
template<class U, std::size_t N>
FLATBUFFERS_CONSTEXPR_CPP11
flatbuffers::span<U, N> make_span(U(&arr)[N]) FLATBUFFERS_NOEXCEPT {
return span<U, N>(arr);
}
template<class U, std::size_t N>
FLATBUFFERS_CONSTEXPR_CPP11
flatbuffers::span<const U, N> make_span(const U(&arr)[N]) FLATBUFFERS_NOEXCEPT {
return span<const U, N>(arr);
}
template<class U, std::size_t N>
FLATBUFFERS_CONSTEXPR_CPP11
flatbuffers::span<U, N> make_span(std::array<U, N> &arr) FLATBUFFERS_NOEXCEPT {
return span<U, N>(arr);
}
template<class U, std::size_t N>
FLATBUFFERS_CONSTEXPR_CPP11
flatbuffers::span<const U, N> make_span(const std::array<U, N> &arr) FLATBUFFERS_NOEXCEPT {
return span<const U, N>(arr);
}
template<class U, std::size_t N>
FLATBUFFERS_CONSTEXPR_CPP11
flatbuffers::span<U, dynamic_extent> make_span(U *first, std::size_t count) FLATBUFFERS_NOEXCEPT {
return span<U, dynamic_extent>(first, count);
}
template<class U, std::size_t N>
FLATBUFFERS_CONSTEXPR_CPP11
flatbuffers::span<const U, dynamic_extent> make_span(const U *first, std::size_t count) FLATBUFFERS_NOEXCEPT {
return span<const U, dynamic_extent>(first, count);
}
#endif // !defined(FLATBUFFERS_SPAN_MINIMAL)
} // namespace flatbuffers
#endif // FLATBUFFERS_STL_EMULATION_H_