Implementing erase/erase_if functions from library fundamentals ts:

base/stl_util_unittest.cc

Index: base/stl_util_unittest.cc
diff --git a/base/stl_util_unittest.cc b/base/stl_util_unittest.cc
index 42004eb869b0424583817f9980b2aa156922c13d..34c5af81cf749065bb612cf504b39e542108dbd7 100644
--- a/base/stl_util_unittest.cc
+++ b/base/stl_util_unittest.cc
@@ -4,8 +4,20 @@
 
 #include "base/stl_util.h"
 
+#include <deque>
+#include <forward_list>
+#include <functional>
+#include <iterator>
+#include <list>
+#include <map>
 #include <set>
+#include <string>
+#include <unordered_map>
+#include <unordered_set>
+#include <vector>
 
+#include "base/strings/string16.h"
+#include "base/strings/utf_string_conversions.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace {
@@ -28,6 +40,51 @@ class ComparableValue {
   int value_;
 };
 
+template <typename Container>
+void RunEraseTest() {
+  const std::pair<Container, Container> test_data[] = {
+      {Container(), Container()}, {{1, 2, 3}, {1, 3}}, {{1, 2, 3, 2}, {1, 3}}};
+
+  for (auto test_case : test_data) {
+    base::Erase(test_case.first, 2);
+    EXPECT_EQ(test_case.second, test_case.first);
+  }
+}
+
+// This test is written for containers of std::pair<int, int> to support maps.
+template <typename Container>
+void RunEraseIfTest() {
+  struct {
+    Container input;
+    Container erase_even;
+    Container erase_odd;
+  } test_data[] = {
+      {Container(), Container(), Container()},
+      {{{1, 1}, {2, 2}, {3, 3}}, {{1, 1}, {3, 3}}, {{2, 2}}},
+      {{{1, 1}, {2, 2}, {3, 3}, {4, 4}}, {{1, 1}, {3, 3}}, {{2, 2}, {4, 4}}},
+  };
+
+  for (auto test_case : test_data) {
+    base::EraseIf(test_case.input, [](const std::pair<int, int>& elem) {
+      return !(elem.first & 1);
+    });
+    EXPECT_EQ(test_case.erase_even, test_case.input);
+  }
+
+  for (auto test_case : test_data) {
+    base::EraseIf(test_case.input, [](const std::pair<int, int>& elem) {
+      return elem.first & 1;
+    });
+    EXPECT_EQ(test_case.erase_odd, test_case.input);
+  }
+}
+
+struct HashByFirst {
+  size_t operator()(const std::pair<int, int>& elem) const {
+    return std::hash<int>()(elem.first);
+  }
+};
+
 }  // namespace
 
 namespace base {
@@ -263,5 +320,92 @@ TEST(StringAsArrayTest, WriteCopy) {
   EXPECT_EQ("abc", s2);
 }
 
+TEST(Erase, String) {
+  const std::pair<std::string, std::string> test_data[] = {
+      {"", ""}, {"abc", "bc"}, {"abca", "bc"},
+  };
+
+  for (auto test_case : test_data) {
+    Erase(test_case.first, 'a');
+    EXPECT_EQ(test_case.second, test_case.first);
+  }
+
+  for (auto test_case : test_data) {
+    EraseIf(test_case.first, [](char elem) { return elem < 'b'; });
+    EXPECT_EQ(test_case.second, test_case.first);
+  }
+}
+
+TEST(Erase, String16) {
+  std::pair<base::string16, base::string16> test_data[] = {
+      {base::string16(), base::string16()},
+      {UTF8ToUTF16("abc"), UTF8ToUTF16("bc")},
+      {UTF8ToUTF16("abca"), UTF8ToUTF16("bc")},
+  };
+
+  const base::string16 letters = UTF8ToUTF16("ab");
+  for (auto test_case : test_data) {
+    Erase(test_case.first, letters[0]);
+    EXPECT_EQ(test_case.second, test_case.first);
+  }
+
+  for (auto test_case : test_data) {
+    EraseIf(test_case.first, [&](short elem) { return elem < letters[1]; });
+    EXPECT_EQ(test_case.second, test_case.first);
+  }
+}
+
+TEST(Erase, Deque) {
+  RunEraseTest<std::deque<int>>();
+  RunEraseIfTest<std::deque<std::pair<int, int>>>();
+}
+
+TEST(Erase, Vector) {
+  RunEraseTest<std::vector<int>>();
+  RunEraseIfTest<std::vector<std::pair<int, int>>>();
+}
+
+TEST(Erase, ForwardList) {
+  RunEraseTest<std::forward_list<int>>();
+  RunEraseIfTest<std::forward_list<std::pair<int, int>>>();
+}
+
+TEST(Erase, List) {
+  RunEraseTest<std::list<int>>();
+  RunEraseIfTest<std::list<std::pair<int, int>>>();
+}
+
+TEST(Erase, Map) {
+  RunEraseIfTest<std::map<int, int>>();
+}
+
+TEST(Erase, Multimap) {
+  RunEraseIfTest<std::multimap<int, int>>();
+}
+
+TEST(Erase, Set) {
+  RunEraseIfTest<std::set<std::pair<int, int>>>();
+}
+
+TEST(Erase, Multiset) {
+  RunEraseIfTest<std::multiset<std::pair<int, int>>>();
+}
+
+TEST(Erase, UnorderedMap) {
+  RunEraseIfTest<std::unordered_map<int, int>>();
+}
+
+TEST(Erase, UnorderedMultimap) {
+  RunEraseIfTest<std::unordered_multimap<int, int>>();
+}
+
+TEST(Erase, UnorderedSet) {
+  RunEraseIfTest<std::unordered_set<std::pair<int, int>, HashByFirst>>();
+}
+
+TEST(Erase, UnorderedMultiset) {
+  RunEraseIfTest<std::unordered_multiset<std::pair<int, int>, HashByFirst>>();
+}
+
 }  // namespace
 }  // namespace base