LLVM 17.0.0git
SetOperations.h
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1//===-- llvm/ADT/SetOperations.h - Generic Set Operations -------*- 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/// \file
10/// This file defines generic set operations that may be used on set's of
11/// different types, and different element types.
12///
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_ADT_SETOPERATIONS_H
16#define LLVM_ADT_SETOPERATIONS_H
17
18namespace llvm {
19
20/// set_union(A, B) - Compute A := A u B, return whether A changed.
21///
22template <class S1Ty, class S2Ty>
23bool set_union(S1Ty &S1, const S2Ty &S2) {
24 bool Changed = false;
25
26 for (typename S2Ty::const_iterator SI = S2.begin(), SE = S2.end();
27 SI != SE; ++SI)
28 if (S1.insert(*SI).second)
29 Changed = true;
30
31 return Changed;
32}
33
34/// set_intersect(A, B) - Compute A := A ^ B
35/// Identical to set_intersection, except that it works on set<>'s and
36/// is nicer to use. Functionally, this iterates through S1, removing
37/// elements that are not contained in S2.
38///
39template <class S1Ty, class S2Ty>
40void set_intersect(S1Ty &S1, const S2Ty &S2) {
41 for (typename S1Ty::iterator I = S1.begin(); I != S1.end();) {
42 const auto &E = *I;
43 ++I;
44 if (!S2.count(E)) S1.erase(E); // Erase element if not in S2
45 }
46}
47
48/// set_difference(A, B) - Return A - B
49///
50template <class S1Ty, class S2Ty>
51S1Ty set_difference(const S1Ty &S1, const S2Ty &S2) {
52 S1Ty Result;
53 for (typename S1Ty::const_iterator SI = S1.begin(), SE = S1.end();
54 SI != SE; ++SI)
55 if (!S2.count(*SI)) // if the element is not in set2
56 Result.insert(*SI);
57 return Result;
58}
59
60/// set_subtract(A, B) - Compute A := A - B
61///
62template <class S1Ty, class S2Ty>
63void set_subtract(S1Ty &S1, const S2Ty &S2) {
64 for (typename S2Ty::const_iterator SI = S2.begin(), SE = S2.end();
65 SI != SE; ++SI)
66 S1.erase(*SI);
67}
68
69/// set_is_subset(A, B) - Return true iff A in B
70///
71template <class S1Ty, class S2Ty>
72bool set_is_subset(const S1Ty &S1, const S2Ty &S2) {
73 if (S1.size() > S2.size())
74 return false;
75 for (const auto It : S1)
76 if (!S2.count(It))
77 return false;
78 return true;
79}
80
81} // End llvm namespace
82
83#endif
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
#define I(x, y, z)
Definition: MD5.cpp:58
@ SI
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
void set_intersect(S1Ty &S1, const S2Ty &S2)
set_intersect(A, B) - Compute A := A ^ B Identical to set_intersection, except that it works on set<>...
Definition: SetOperations.h:40
bool set_is_subset(const S1Ty &S1, const S2Ty &S2)
set_is_subset(A, B) - Return true iff A in B
Definition: SetOperations.h:72
void set_subtract(S1Ty &S1, const S2Ty &S2)
set_subtract(A, B) - Compute A := A - B
Definition: SetOperations.h:63
bool set_union(S1Ty &S1, const S2Ty &S2)
set_union(A, B) - Compute A := A u B, return whether A changed.
Definition: SetOperations.h:23
S1Ty set_difference(const S1Ty &S1, const S2Ty &S2)
set_difference(A, B) - Return A - B
Definition: SetOperations.h:51