[SetVector] Add erase() method

This is a recommit of r264414 after fixing the buildbot failure caused by
incompatible use of std::vector.erase().

The original message:

Add erase() which returns an iterator pointing to the next element after the
erased one. This makes it possible to erase selected elements while iterating
over the SetVector :
  while (I != E)
    if (test(*I))
      I = SetVector.erase(I);
    else
      ++I;

Reviewers: qcolombet, mcrosier, MatzeB, dblaikie

Subscribers: dberlin, dblaikie, mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D18281

llvm-svn: 264450

1 files changed, 34 insertions, 0 deletions

diff --git a/llvm/unittests/ADT/SetVectorTest.cpp b/llvm/unittests/ADT/SetVectorTest.cpp
new file mode 100644
index 0000000..b8cac0d
--- /dev/null
+++ b/llvm/unittests/ADT/SetVectorTest.cpp
@@ -0,0 +1,34 @@
+//===- llvm/unittest/ADT/SetVector.cpp ------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// SetVector unit tests.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/SetVector.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+
+TEST(SetVector, EraseTest) {
+  SetVector<int> S;
+  S.insert(0);
+  S.insert(1);
+  S.insert(2);
+
+  auto I = S.erase(std::next(S.begin()));
+
+  // Test that the returned iterator is the expected one-after-erase
+  // and the size/contents is the expected sequence {0, 2}.
+  EXPECT_EQ(std::next(S.begin()), I);
+  EXPECT_EQ(2u, S.size());
+  EXPECT_EQ(0, *S.begin());
+  EXPECT_EQ(2, *std::next(S.begin()));
+}
+