diff options
Diffstat (limited to 'absl/types/span.h')
-rw-r--r-- | absl/types/span.h | 55 |
1 files changed, 34 insertions, 21 deletions
diff --git a/absl/types/span.h b/absl/types/span.h index 1b5edf25..99b6765b 100644 --- a/absl/types/span.h +++ b/absl/types/span.h @@ -72,7 +72,7 @@ #include "absl/meta/type_traits.h" namespace absl { -inline namespace lts_2018_06_20 { +inline namespace lts_2018_12_18 { template <typename T> class Span; @@ -88,7 +88,7 @@ constexpr auto GetDataImpl(C& c, char) noexcept // NOLINT(runtime/references) return c.data(); } -// Before C++17, std::string::data returns a const char* in all cases. +// Before C++17, string::data returns a const char* in all cases. inline char* GetDataImpl(std::string& s, // NOLINT(runtime/references) int) noexcept { return &s[0]; @@ -380,64 +380,70 @@ class Span { // // Returns a reference to the i'th element of this span. constexpr reference at(size_type i) const { - return ABSL_PREDICT_TRUE(i < size()) - ? ptr_[i] + return ABSL_PREDICT_TRUE(i < size()) // + ? *(data() + i) : (base_internal::ThrowStdOutOfRange( "Span::at failed bounds check"), - ptr_[i]); + *(data() + i)); } // Span::front() // // Returns a reference to the first element of this span. - reference front() const noexcept { return ABSL_ASSERT(size() > 0), ptr_[0]; } + constexpr reference front() const noexcept { + return ABSL_ASSERT(size() > 0), *data(); + } // Span::back() // // Returns a reference to the last element of this span. - reference back() const noexcept { - return ABSL_ASSERT(size() > 0), ptr_[size() - 1]; + constexpr reference back() const noexcept { + return ABSL_ASSERT(size() > 0), *(data() + size() - 1); } // Span::begin() // // Returns an iterator to the first element of this span. - constexpr iterator begin() const noexcept { return ptr_; } + constexpr iterator begin() const noexcept { return data(); } // Span::cbegin() // // Returns a const iterator to the first element of this span. - constexpr const_iterator cbegin() const noexcept { return ptr_; } + constexpr const_iterator cbegin() const noexcept { return begin(); } // Span::end() // // Returns an iterator to the last element of this span. - iterator end() const noexcept { return ptr_ + len_; } + constexpr iterator end() const noexcept { return data() + size(); } // Span::cend() // // Returns a const iterator to the last element of this span. - const_iterator cend() const noexcept { return end(); } + constexpr const_iterator cend() const noexcept { return end(); } // Span::rbegin() // // Returns a reverse iterator starting at the last element of this span. - reverse_iterator rbegin() const noexcept { return reverse_iterator(end()); } + constexpr reverse_iterator rbegin() const noexcept { + return reverse_iterator(end()); + } // Span::crbegin() // // Returns a reverse const iterator starting at the last element of this span. - const_reverse_iterator crbegin() const noexcept { return rbegin(); } + constexpr const_reverse_iterator crbegin() const noexcept { return rbegin(); } // Span::rend() // // Returns a reverse iterator starting at the first element of this span. - reverse_iterator rend() const noexcept { return reverse_iterator(begin()); } + constexpr reverse_iterator rend() const noexcept { + return reverse_iterator(begin()); + } // Span::crend() // // Returns a reverse iterator starting at the first element of this span. - const_reverse_iterator crend() const noexcept { return rend(); } + constexpr const_reverse_iterator crend() const noexcept { return rend(); } // Span mutations @@ -445,7 +451,7 @@ class Span { // // Removes the first `n` elements from the span. void remove_prefix(size_type n) noexcept { - assert(len_ >= n); + assert(size() >= n); ptr_ += n; len_ -= n; } @@ -454,7 +460,7 @@ class Span { // // Removes the last `n` elements from the span. void remove_suffix(size_type n) noexcept { - assert(len_ >= n); + assert(size() >= n); len_ -= n; } @@ -475,11 +481,18 @@ class Span { // absl::MakeSpan(vec).subspan(4); // {} // absl::MakeSpan(vec).subspan(5); // throws std::out_of_range constexpr Span subspan(size_type pos = 0, size_type len = npos) const { - return (pos <= len_) - ? Span(ptr_ + pos, span_internal::Min(len_ - pos, len)) + return (pos <= size()) + ? Span(data() + pos, span_internal::Min(size() - pos, len)) : (base_internal::ThrowStdOutOfRange("pos > size()"), Span()); } + // Support for absl::Hash. + template <typename H> + friend H AbslHashValue(H h, Span v) { + return H::combine(H::combine_contiguous(std::move(h), v.data(), v.size()), + v.size()); + } + private: pointer ptr_; size_type len_; @@ -746,6 +759,6 @@ template <int&... ExplicitArgumentBarrier, typename T, size_t N> constexpr Span<const T> MakeConstSpan(const T (&array)[N]) noexcept { return Span<const T>(array, N); } -} // inline namespace lts_2018_06_20 +} // inline namespace lts_2018_12_18 } // namespace absl #endif // ABSL_TYPES_SPAN_H_ |