| // Copyright 2020 The Dawn & Tint Authors |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are met: |
| // |
| // 1. Redistributions of source code must retain the above copyright notice, this |
| // list of conditions and the following disclaimer. |
| // |
| // 2. Redistributions in binary form must reproduce the above copyright notice, |
| // this list of conditions and the following disclaimer in the documentation |
| // and/or other materials provided with the distribution. |
| // |
| // 3. Neither the name of the copyright holder nor the names of its |
| // contributors may be used to endorse or promote products derived from |
| // this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| // DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE |
| // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
| // SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
| // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| #ifndef SRC_DAWN_COMMON_ITYP_SPAN_H_ |
| #define SRC_DAWN_COMMON_ITYP_SPAN_H_ |
| |
| #include <type_traits> |
| |
| #include "dawn/common/TypedInteger.h" |
| #include "dawn/common/UnderlyingType.h" |
| |
| namespace dawn::ityp { |
| |
| // ityp::span is a helper class that wraps an unowned packed array of type |Value|. |
| // It stores the size and pointer to first element. It has the restriction that |
| // indices must be a particular type |Index|. This provides a type-safe way to index |
| // raw pointers. |
| template <typename Index, typename Value> |
| class span { |
| using I = UnderlyingType<Index>; |
| |
| public: |
| constexpr span() : mData(nullptr), mSize(0) {} |
| constexpr span(Value* data, Index size) : mData(data), mSize(size) {} |
| |
| constexpr Value& operator[](Index i) const { |
| DAWN_ASSERT(i < mSize); |
| return mData[static_cast<I>(i)]; |
| } |
| |
| Value* data() noexcept { return mData; } |
| |
| const Value* data() const noexcept { return mData; } |
| |
| Value* begin() noexcept { return mData; } |
| |
| const Value* begin() const noexcept { return mData; } |
| |
| Value* end() noexcept { return mData + static_cast<I>(mSize); } |
| |
| const Value* end() const noexcept { return mData + static_cast<I>(mSize); } |
| |
| Value& front() { |
| DAWN_ASSERT(mData != nullptr); |
| DAWN_ASSERT(static_cast<I>(mSize) >= 0); |
| return *mData; |
| } |
| |
| const Value& front() const { |
| DAWN_ASSERT(mData != nullptr); |
| DAWN_ASSERT(static_cast<I>(mSize) >= 0); |
| return *mData; |
| } |
| |
| Value& back() { |
| DAWN_ASSERT(mData != nullptr); |
| DAWN_ASSERT(static_cast<I>(mSize) >= 0); |
| return *(mData + static_cast<I>(mSize) - 1); |
| } |
| |
| const Value& back() const { |
| DAWN_ASSERT(mData != nullptr); |
| DAWN_ASSERT(static_cast<I>(mSize) >= 0); |
| return *(mData + static_cast<I>(mSize) - 1); |
| } |
| |
| Index size() const { return mSize; } |
| |
| private: |
| Value* mData; |
| Index mSize; |
| }; |
| |
| } // namespace dawn::ityp |
| |
| #endif // SRC_DAWN_COMMON_ITYP_SPAN_H_ |