1 /* 2 * Copyright 2018 Google Inc. 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8 #ifndef SkSpan_DEFINED 9 #define SkSpan_DEFINED 10 11 #include <cstddef> 12 #include <vector> 13 14 template <typename T> 15 class SkSpan { 16 public: 17 template <size_t N> SkSpan(T (& t)[N])18 constexpr SkSpan(T(&t)[N]) : fPtr(t), fSize(N) {} SkSpan()19 constexpr SkSpan() : fPtr{nullptr}, fSize{0} {} SkSpan(T * ptr,size_t size)20 constexpr SkSpan(T* ptr, size_t size) : fPtr{ptr}, fSize{size} {} 21 template <typename U> SkSpan(std::vector<U> & v)22 constexpr explicit SkSpan(std::vector<U>& v) : fPtr{v.data()}, fSize{v.size()} {} 23 constexpr SkSpan(const SkSpan& o) = default; 24 constexpr SkSpan& operator=(const SkSpan& that) { 25 fPtr = that.fPtr; 26 fSize = that.fSize; 27 return *this; 28 } 29 constexpr T& operator [] (size_t i) const { return fPtr[i]; } begin()30 constexpr T* begin() const { return fPtr; } end()31 constexpr T* end() const { return fPtr + fSize; } cbegin()32 constexpr const T* cbegin() const { return fPtr; } cend()33 constexpr const T* cend() const { return fPtr + fSize; } data()34 constexpr T* data() const { return fPtr; } size()35 constexpr size_t size() const { return fSize; } empty()36 constexpr bool empty() const { return fSize == 0; } size_bytes()37 constexpr size_t size_bytes() const { return fSize * sizeof(T); } toConst()38 constexpr SkSpan<const T> toConst() const { return SkSpan<const T>{fPtr, fSize}; } first(size_t prefixLen)39 constexpr SkSpan<T> first(size_t prefixLen) { return SkSpan<T>{fPtr, prefixLen}; } 40 41 private: 42 T* fPtr; 43 size_t fSize; 44 }; 45 46 #endif // SkSpan_DEFINED 47