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
21namespace orc_rt {
22
23constexpr 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.
27template <typename T, std::size_t Extent = dynamic_extent> class span {
28public:
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
56private:
57 T *Data = nullptr;
58 size_type Size = 0;
59};
60
61} // namespace orc_rt
62
63#endif // ORC_RT_ADT_H
64