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- /*
- * Copyright 2018 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
- #ifndef SkSpan_DEFINED
- #define SkSpan_DEFINED
- #include <cstddef>
- #include <string>
- #include <vector>
- #include "include/private/SkTo.h"
- template <typename T>
- class SkSpan {
- public:
- constexpr SkSpan() : fPtr{nullptr}, fSize{0} {}
- constexpr SkSpan(T* ptr, size_t size) : fPtr{ptr}, fSize{size} {}
- template <typename U, typename = typename std::enable_if<std::is_same<const U, T>::value>::type>
- constexpr SkSpan(const SkSpan<U>& that) : fPtr(that.data()), fSize{that.size()} {}
- constexpr SkSpan(const SkSpan& o) = default;
- constexpr SkSpan& operator=(const SkSpan& that) {
- fPtr = that.fPtr;
- fSize = that.fSize;
- return *this;
- }
- constexpr T& operator [] (size_t i) const { return fPtr[i]; }
- constexpr T& front() const { return fPtr[0]; }
- constexpr T& back() const { return fPtr[fSize - 1]; }
- constexpr T* begin() const { return fPtr; }
- constexpr T* end() const { return fPtr + fSize; }
- constexpr const T* cbegin() const { return fPtr; }
- constexpr const T* cend() const { return fPtr + fSize; }
- constexpr T* data() const { return fPtr; }
- constexpr size_t size() const { return fSize; }
- constexpr bool empty() const { return fSize == 0; }
- constexpr size_t size_bytes() const { return fSize * sizeof(T); }
- constexpr SkSpan<T> first(size_t prefixLen) { return SkSpan<T>{fPtr, prefixLen}; }
- private:
- T* fPtr;
- size_t fSize;
- };
- template <typename T, typename S>
- inline constexpr SkSpan<T> SkMakeSpan(T* p, S s) { return SkSpan<T>{p, SkTo<size_t>(s)}; }
- template <size_t N, typename T>
- inline constexpr SkSpan<T> SkMakeSpan(T(&a)[N]) { return SkSpan<T>{a, N}; }
- // This takes a const Container& to create an immutable span.
- template <typename Container>
- inline auto SkMakeSpan(const Container& c)
- -> SkSpan<typename std::remove_reference<decltype(*(c.data()))>::type> {
- return {c.data(), c.size()};
- }
- #endif // SkSpan_DEFINED
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