LLVM  9.0.0svn
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 // 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 
68 } // End llvm namespace
69 
70 #endif
This class represents lattice values for constants.
Definition: AllocatorList.h:23
S1Ty set_difference(const S1Ty &S1, const S2Ty &S2)
set_difference(A, B) - Return A - B
Definition: SetOperations.h:50
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:39
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
void set_subtract(S1Ty &S1, const S2Ty &S2)
set_subtract(A, B) - Compute A := A - B
Definition: SetOperations.h:62
#define I(x, y, z)
Definition: MD5.cpp:58
bool set_union(S1Ty &S1, const S2Ty &S2)
set_union(A, B) - Compute A := A u B, return whether A changed.
Definition: SetOperations.h:22