1//===- Sequence.h - Utility for producing sequences of values ---*- 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/// \file
9/// This routine provides some synthesis utilities to produce sequences of
10/// values. The names are intentionally kept very short as they tend to occur
11/// in common and widely used contexts.
12///
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_ADT_SEQUENCE_H
16#define LLVM_ADT_SEQUENCE_H
17
18#include "llvm/ADT/iterator.h"
19#include "llvm/ADT/iterator_range.h"
20#include <algorithm>
21#include <iterator>
22#include <utility>
23
24namespace llvm {
25
26namespace detail {
27
28template <typename ValueT>
29class value_sequence_iterator
30 : public iterator_facade_base<value_sequence_iterator<ValueT>,
31 std::random_access_iterator_tag,
32 const ValueT> {
33 using BaseT = typename value_sequence_iterator::iterator_facade_base;
34
35 ValueT Value;
36
37public:
38 using difference_type = typename BaseT::difference_type;
39 using reference = typename BaseT::reference;
40
41 value_sequence_iterator() = default;
42 value_sequence_iterator(const value_sequence_iterator &) = default;
43 value_sequence_iterator(value_sequence_iterator &&Arg)
44 : Value(std::move(Arg.Value)) {}
45 value_sequence_iterator &operator=(const value_sequence_iterator &Arg) {
46 Value = Arg.Value;
47 return *this;
48 }
49
50 template <typename U, typename Enabler = decltype(ValueT(std::declval<U>()))>
51 value_sequence_iterator(U &&Value) : Value(std::forward<U>(Value)) {}
52
53 value_sequence_iterator &operator+=(difference_type N) {
54 Value += N;
55 return *this;
56 }
57 value_sequence_iterator &operator-=(difference_type N) {
58 Value -= N;
59 return *this;
60 }
61 using BaseT::operator-;
62 difference_type operator-(const value_sequence_iterator &RHS) const {
63 return Value - RHS.Value;
64 }
65
66 bool operator==(const value_sequence_iterator &RHS) const {
67 return Value == RHS.Value;
68 }
69 bool operator<(const value_sequence_iterator &RHS) const {
70 return Value < RHS.Value;
71 }
72
73 reference operator*() const { return Value; }
74};
75
76} // end namespace detail
77
78template <typename ValueT>
79iterator_range<detail::value_sequence_iterator<ValueT>> seq(ValueT Begin,
80 ValueT End) {
81 return make_range(detail::value_sequence_iterator<ValueT>(Begin),
82 detail::value_sequence_iterator<ValueT>(End));
83}
84
85} // end namespace llvm
86
87#endif // LLVM_ADT_SEQUENCE_H
88