1 //===-- llvm/ADT/SetOperations.h - Generic Set Operations -------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines generic set operations that may be used on set's of
11 // different types, and different element types.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_ADT_SETOPERATIONS_H
16 #define LLVM_ADT_SETOPERATIONS_H
20 /// set_union(A, B) - Compute A := A u B, return whether A changed.
22 template <class S1Ty, class S2Ty>
23 bool set_union(S1Ty &S1, const S2Ty &S2) {
26 for (typename S2Ty::const_iterator SI = S2.begin(), SE = S2.end();
28 if (S1.insert(*SI).second)
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.
39 template <class S1Ty, class S2Ty>
40 void set_intersect(S1Ty &S1, const S2Ty &S2) {
41 for (typename S1Ty::iterator I = S1.begin(); I != S1.end();) {
42 const typename S1Ty::key_type &E = *I;
44 if (!S2.count(E)) S1.erase(E); // Erase element if not in S2
48 /// set_difference(A, B) - Return A - B
50 template <class S1Ty, class S2Ty>
51 S1Ty set_difference(const S1Ty &S1, const S2Ty &S2) {
53 for (typename S1Ty::const_iterator SI = S1.begin(), SE = S1.end();
55 if (!S2.count(*SI)) // if the element is not in set2
60 /// set_subtract(A, B) - Compute A := A - B
62 template <class S1Ty, class S2Ty>
63 void set_subtract(S1Ty &S1, const S2Ty &S2) {
64 for (typename S2Ty::const_iterator SI = S2.begin(), SE = S2.end();
69 } // End llvm namespace