Cut FOR_EACH_KV

Summary: [Folly] Cut the FOR_EACH_KV macro, which may be replaced by a combination of range-for and structured bindings.

Differential Revision: D21826182

fbshipit-source-id: ce4712afd3d0d7806eb1fca8c97009da117f982e

folly/container/Foreach.h

@@ -159,35 +159,6 @@ constexpr decltype(auto) fetch(Sequence&& sequence, Index&& index);
     for (auto&& _FE_ANON(s2_) = (c); !_FE_ANON(s1_); _FE_ANON(s1_) = true) \
       for (auto i = _FE_ANON(s2_).rbegin(); i != _FE_ANON(s2_).rend(); ++i)
 
-/**
- * If you just want the keys, please use this (ranges-v3) construct:
- *
- *    for (auto&& element : collection | views::keys)
- *
- * If you just want the values, please use this (ranges-v3) construct:
- *
- *    for (auto&& element : collection | views::values)
- *
- * If you need to see both, use:
- *
- *    for (auto&& element : collection) {
- *      auto const& key = element.first;
- *      auto& value = element.second;
- *      ......
- *    }
- *
- */
-#define FOR_EACH_KV(k, v, c)                                                  \
-  if (unsigned int _FE_ANON(s1_) = 0) {                                       \
-  } else                                                                      \
-    for (auto&& _FE_ANON(s2_) = (c); !_FE_ANON(s1_); _FE_ANON(s1_) = 1)       \
-      for (auto _FE_ANON(s3_) = _FE_ANON(s2_).begin();                        \
-           _FE_ANON(s3_) != _FE_ANON(s2_).end();                              \
-           _FE_ANON(s1_) == 2 ? ((_FE_ANON(s1_) = 0), ++_FE_ANON(s3_))        \
-                              : (_FE_ANON(s3_) = _FE_ANON(s2_).end()))        \
-        for (auto& k = _FE_ANON(s3_)->first; !_FE_ANON(s1_); ++_FE_ANON(s1_)) \
-          for (auto& v = _FE_ANON(s3_)->second; !_FE_ANON(s1_); ++_FE_ANON(s1_))
-
 namespace folly {
 namespace detail {
 

folly/container/test/ForeachBenchmark.cpp

@@ -30,7 +30,6 @@ using namespace folly;
 //    iter->first and iter->second to local vars inside the FOR_EACH loop.
 // 2. Benchmark iterating through the man with FOR_EACH, but use iter->first and
 //    iter->second as is, without assigning to local variables.
-// 3. Use FOR_EACH_KV loop to iterate through the map.
 
 // For use in benchmarks below.
 std::map<int, std::string> bmMap;
@@ -305,20 +304,6 @@ BENCHMARK(ForEachKVNoMacroNoAssign, iters) {
   }
 }
 
-BENCHMARK(ForEachKVMacro, iters) {
-  int sumKeys = 0;
-  std::string sumValues;
-
-  BENCHMARK_SUSPEND {
-    setupBenchmark(iters);
-  }
-
-  FOR_EACH_KV (k, v, bmMap) {
-    sumKeys += k;
-    sumValues += v;
-  }
-}
-
 BENCHMARK(ForEachManual, iters) {
   int sum = 1;
   for (size_t i = 1; i < iters; ++i) {

folly/container/test/ForeachTest.cpp

@@ -340,56 +340,3 @@ TEST(Foreach, ForEachNested) {
   auto len = hello.size();
   EXPECT_EQ(len * len, n);
 }
-
-TEST(Foreach, ForEachKV) {
-  std::map<std::string, int> testMap;
-  testMap["abc"] = 1;
-  testMap["def"] = 2;
-  std::string keys = "";
-  int values = 0;
-  int numEntries = 0;
-  FOR_EACH_KV (key, value, testMap) {
-    keys += key;
-    values += value;
-    ++numEntries;
-  }
-  EXPECT_EQ("abcdef", keys);
-  EXPECT_EQ(3, values);
-  EXPECT_EQ(2, numEntries);
-}
-
-TEST(Foreach, ForEachKVBreak) {
-  std::map<std::string, int> testMap;
-  testMap["abc"] = 1;
-  testMap["def"] = 2;
-  std::string keys = "";
-  int values = 0;
-  int numEntries = 0;
-  FOR_EACH_KV (key, value, testMap) {
-    keys += key;
-    values += value;
-    ++numEntries;
-    break;
-  }
-  EXPECT_EQ("abc", keys);
-  EXPECT_EQ(1, values);
-  EXPECT_EQ(1, numEntries);
-}
-
-TEST(Foreach, ForEachKvWithMultiMap) {
-  std::multimap<std::string, int> testMap;
-  testMap.insert(std::make_pair("abc", 1));
-  testMap.insert(std::make_pair("abc", 2));
-  testMap.insert(std::make_pair("def", 3));
-  std::string keys = "";
-  int values = 0;
-  int numEntries = 0;
-  FOR_EACH_KV (key, value, testMap) {
-    keys += key;
-    values += value;
-    ++numEntries;
-  }
-  EXPECT_EQ("abcabcdef", keys);
-  EXPECT_EQ(6, values);
-  EXPECT_EQ(3, numEntries);
-}