1 //===----------------------- adt.h - Handy ADTs -----------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file is a part of the ORC runtime support library. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #ifndef ORC_RT_ADT_H 14 #define ORC_RT_ADT_H 15 16 #include <cstring> 17 #include <limits> 18 #include <ostream> 19 #include <string> 20 21 namespace __orc_rt { 22 23 constexpr std::size_t dynamic_extent = std::numeric_limits<std::size_t>::max(); 24 25 /// A substitute for std::span (and llvm::ArrayRef). 26 /// FIXME: Remove in favor of std::span once we can use c++20. 27 template <typename T, std::size_t Extent = dynamic_extent> class span { 28 public: 29 typedef T element_type; 30 typedef std::remove_cv<T> value_type; 31 typedef std::size_t size_type; 32 typedef std::ptrdiff_t difference_type; 33 typedef T *pointer; 34 typedef const T *const_pointer; 35 typedef T &reference; 36 typedef const T &const_reference; 37 38 typedef pointer iterator; 39 40 static constexpr std::size_t extent = Extent; 41 42 constexpr span() noexcept = default; 43 constexpr span(T *first, size_type count) noexcept 44 : Data(first), Size(count) {} 45 46 template <std::size_t N> 47 constexpr span(T (&arr)[N]) noexcept : Data(&arr[0]), Size(N) {} 48 49 constexpr iterator begin() const noexcept { return Data; } 50 constexpr iterator end() const noexcept { return Data + Size; } 51 constexpr pointer data() const noexcept { return Data; } 52 constexpr reference operator[](size_type idx) const { return Data[idx]; } 53 constexpr size_type size() const noexcept { return Size; } 54 constexpr bool empty() const noexcept { return Size == 0; } 55 56 private: 57 T *Data = nullptr; 58 size_type Size = 0; 59 }; 60 61 } // end namespace __orc_rt 62 63 #endif // ORC_RT_ADT_H 64