[ADT] Rewrite mapped_iterator in terms of iterator_adaptor_base.
Summary:
This eliminates the boilerplate implementation of the iterator interface in
mapped_iterator.
This patch also adds unit tests that verify that the mapped function is applied
by operator* and operator->, and that references returned by the map function
are returned via operator*.
Reviewers: dblaikie, chandlerc
Subscribers: llvm-commits, mgorny
Differential Revision: https://reviews.llvm.org/D39855
llvm-svn: 317902
diff --git a/llvm/unittests/ADT/MappedIteratorTest.cpp b/llvm/unittests/ADT/MappedIteratorTest.cpp
new file mode 100644
index 0000000..d8c48a7
--- /dev/null
+++ b/llvm/unittests/ADT/MappedIteratorTest.cpp
@@ -0,0 +1,51 @@
+//===------ MappedIteratorTest.cpp - Unit tests for mapped_iterator -------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/STLExtras.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+
+namespace {
+
+TEST(MappedIteratorTest, ApplyFunctionOnDereference) {
+ std::vector<int> V({0});
+
+ auto I = map_iterator(V.begin(), [](int X) { return X + 1; });
+
+ EXPECT_EQ(*I, 1) << "should have applied function in dereference";
+}
+
+TEST(MappedIteratorTest, ApplyFunctionOnArrow) {
+ struct S {
+ int Z = 0;
+ };
+
+ std::vector<int> V({0});
+ S Y;
+ S* P = &Y;
+
+ auto I = map_iterator(V.begin(), [&](int X) -> S& { return *(P + X); });
+
+ I->Z = 42;
+
+ EXPECT_EQ(Y.Z, 42) << "should have applied function during arrow";
+}
+
+TEST(MappedIteratorTest, FunctionPreservesReferences) {
+ std::vector<int> V({1});
+ std::map<int, int> M({ {1, 1} });
+
+ auto I = map_iterator(V.begin(), [&](int X) -> int& { return M[X]; });
+ *I = 42;
+
+ EXPECT_EQ(M[1], 42) << "assignment should have modified M";
+}
+
+} // anonymous namespace