Add method get_keys from unordered map (#65)

Signed-off-by: Juan López Fernández <juanlopez@eprosima.com>

Author: juanlofer-eprosima

cpp_utils/include/cpp_utils/impl/utils.ipp

@@ -177,5 +177,17 @@ std::set<Key> get_keys(
     return ret;
 }
 
+template <typename Key, typename Value>
+std::set<Key> get_keys(
+        const std::unordered_map<Key, Value>& map)
+{
+    std::set<Key> ret;
+    for (const auto& elem : map)
+    {
+        ret.insert(elem.first);
+    }
+    return ret;
+}
+
 } /* namespace utils */
 } /* namespace eprosima */

cpp_utils/include/cpp_utils/utils.hpp

@@ -25,6 +25,7 @@
 #include <set>
 #include <sstream>
 #include <string>
+#include <unordered_map>
 #include <vector>
 
 #include <cpp_utils/macros/macros.hpp>
@@ -288,6 +289,11 @@ CPP_UTILS_DllAPI
 std::set<Key> get_keys(
         const std::map<Key, Value>& map);
 
+template <typename Key, typename Value>
+CPP_UTILS_DllAPI
+std::set<Key> get_keys(
+        const std::unordered_map<Key, Value>& map);
+
 } /* namespace utils */
 } /* namespace eprosima */
 

cpp_utils/test/unittest/utils/CMakeLists.txt

@@ -35,7 +35,8 @@ set(TEST_LIST
         split_string_one_delimiter
         split_strings_one_delimiter
         split_string_delimiters
-        get_keys
+        get_map_keys
+        get_unordered_map_keys
     )
 
 set(TEST_EXTRA_LIBRARIES

cpp_utils/test/unittest/utils/utilsTest.cpp

@@ -580,9 +580,9 @@ TEST(utilsTest, split_string_delimiters)
 }
 
 /**
- * Test method get_keys
+ * Test method get_keys from std::map
  */
-TEST(utilsTest, get_keys)
+TEST(utilsTest, get_map_keys)
 {
     // std::string keys
     {
@@ -609,6 +609,36 @@ TEST(utilsTest, get_keys)
     }
 }
 
+/**
+ * Test method get_keys from std::unordered_map
+ */
+TEST(utilsTest, get_unordered_map_keys)
+{
+    // std::string keys
+    {
+        std::set<std::string> keys = {"a", "b", "c", "d"};
+        std::unordered_map<std::string, std::string> map;
+        for (auto key: keys)
+        {
+            map.emplace(key, "value");
+        }
+
+        ASSERT_EQ(keys, get_keys(map));
+    }
+
+    // int keys
+    {
+        std::set<int> keys = {1, 2, 3, 4};
+        std::unordered_map<int, std::string> map;
+        for (auto key: keys)
+        {
+            map.emplace(key, "value");
+        }
+
+        ASSERT_EQ(keys, get_keys(map));
+    }
+}
+
 int main(
         int argc,
         char** argv)