Andrew Scull | 5e1ddfa | 2018-08-14 10:06:54 +0100 | [diff] [blame] | 1 | //===-- llvm/ADT/SetOperations.h - Generic Set Operations -------*- C++ -*-===// |
| 2 | // |
Andrew Walbran | 16937d0 | 2019-10-22 13:54:20 +0100 | [diff] [blame] | 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 |
Andrew Scull | 5e1ddfa | 2018-08-14 10:06:54 +0100 | [diff] [blame] | 6 | // |
| 7 | //===----------------------------------------------------------------------===// |
| 8 | // |
| 9 | // This file defines generic set operations that may be used on set's of |
| 10 | // different types, and different element types. |
| 11 | // |
| 12 | //===----------------------------------------------------------------------===// |
| 13 | |
| 14 | #ifndef LLVM_ADT_SETOPERATIONS_H |
| 15 | #define LLVM_ADT_SETOPERATIONS_H |
| 16 | |
| 17 | namespace llvm { |
| 18 | |
| 19 | /// set_union(A, B) - Compute A := A u B, return whether A changed. |
| 20 | /// |
| 21 | template <class S1Ty, class S2Ty> |
| 22 | bool set_union(S1Ty &S1, const S2Ty &S2) { |
| 23 | bool Changed = false; |
| 24 | |
| 25 | for (typename S2Ty::const_iterator SI = S2.begin(), SE = S2.end(); |
| 26 | SI != SE; ++SI) |
| 27 | if (S1.insert(*SI).second) |
| 28 | Changed = true; |
| 29 | |
| 30 | return Changed; |
| 31 | } |
| 32 | |
| 33 | /// set_intersect(A, B) - Compute A := A ^ B |
| 34 | /// Identical to set_intersection, except that it works on set<>'s and |
| 35 | /// is nicer to use. Functionally, this iterates through S1, removing |
| 36 | /// elements that are not contained in S2. |
| 37 | /// |
| 38 | template <class S1Ty, class S2Ty> |
| 39 | void set_intersect(S1Ty &S1, const S2Ty &S2) { |
| 40 | for (typename S1Ty::iterator I = S1.begin(); I != S1.end();) { |
| 41 | const auto &E = *I; |
| 42 | ++I; |
| 43 | if (!S2.count(E)) S1.erase(E); // Erase element if not in S2 |
| 44 | } |
| 45 | } |
| 46 | |
| 47 | /// set_difference(A, B) - Return A - B |
| 48 | /// |
| 49 | template <class S1Ty, class S2Ty> |
| 50 | S1Ty set_difference(const S1Ty &S1, const S2Ty &S2) { |
| 51 | S1Ty Result; |
| 52 | for (typename S1Ty::const_iterator SI = S1.begin(), SE = S1.end(); |
| 53 | SI != SE; ++SI) |
| 54 | if (!S2.count(*SI)) // if the element is not in set2 |
| 55 | Result.insert(*SI); |
| 56 | return Result; |
| 57 | } |
| 58 | |
| 59 | /// set_subtract(A, B) - Compute A := A - B |
| 60 | /// |
| 61 | template <class S1Ty, class S2Ty> |
| 62 | void set_subtract(S1Ty &S1, const S2Ty &S2) { |
| 63 | for (typename S2Ty::const_iterator SI = S2.begin(), SE = S2.end(); |
| 64 | SI != SE; ++SI) |
| 65 | S1.erase(*SI); |
| 66 | } |
| 67 | |
Olivier Deprez | f4ef2d0 | 2021-04-20 13:36:24 +0200 | [diff] [blame] | 68 | /// set_is_subset(A, B) - Return true iff A in B |
| 69 | /// |
| 70 | template <class S1Ty, class S2Ty> |
| 71 | bool set_is_subset(const S1Ty &S1, const S2Ty &S2) { |
| 72 | if (S1.size() > S2.size()) |
| 73 | return false; |
| 74 | for (auto &It : S1) |
| 75 | if (!S2.count(It)) |
| 76 | return false; |
| 77 | return true; |
| 78 | } |
| 79 | |
| 80 | /// set_is_strict_subset(A, B) - Return true iff A in B and and A != B |
| 81 | /// |
| 82 | template <class S1Ty, class S2Ty> |
| 83 | bool set_is_strict_subset(const S1Ty &S1, const S2Ty &S2) { |
| 84 | if (S1.size() >= S2.size()) |
| 85 | return false; |
| 86 | return set_is_subset(S1, S2); |
| 87 | } |
| 88 | |
Andrew Scull | 5e1ddfa | 2018-08-14 10:06:54 +0100 | [diff] [blame] | 89 | } // End llvm namespace |
| 90 | |
| 91 | #endif |