Add method get_keys from map (#60)

* Add method get_keys from map

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

* Fix header dll export order

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

* Add docstring and test

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

---------

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

Author: juanlofer-eprosima

cpp_utils/include/cpp_utils/impl/utils.ipp

@@ -165,5 +165,17 @@ void* copy_to_void_ptr(
     return new_ptr;
 }
 
+template <typename Key, typename Value>
+std::set<Key> get_keys(
+        const std::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

@@ -20,6 +20,7 @@
 
 #pragma once
 
+#include <map>
 #include <memory>
 #include <set>
 #include <sstream>
@@ -273,6 +274,20 @@ std::vector<std::string> split_string(
         const std::string& source,
         const std::string& delimiter);
 
+/**
+ * @brief Get std::map keys.
+ *
+ * Obtain the set of keys relative to a std::map.
+ *
+ * @param map [in] map whose keys are returned
+ *
+ * @return map keys
+ */
+template <typename Key, typename Value>
+CPP_UTILS_DllAPI
+std::set<Key> get_keys(
+        const std::map<Key, Value>& map);
+
 } /* namespace utils */
 } /* namespace eprosima */
 

cpp_utils/src/cpp/utils.cpp

@@ -116,7 +116,7 @@ bool is_file_accessible(
     if ((FileAccessMode::exec& access_mode) == FileAccessMode::exec)
     {
         logWarning(
-            DDSROUTER_UTILS,
+            UTILS_UTILS,
             "Windows does not allow to check execution permission for file.");
         // Take out the FileAccessMode::exec bit
         access_mode =

cpp_utils/test/unittest/utils/CMakeLists.txt

@@ -35,6 +35,7 @@ set(TEST_LIST
         split_string_one_delimiter
         split_strings_one_delimiter
         split_string_delimiters
+        get_keys
     )
 
 set(TEST_EXTRA_LIBRARIES

cpp_utils/test/unittest/utils/utilsTest.cpp

@@ -579,6 +579,36 @@ TEST(utilsTest, split_string_delimiters)
     }
 }
 
+/**
+ * Test method get_keys
+ */
+TEST(utilsTest, get_keys)
+{
+    // std::string keys
+    {
+        std::set<std::string> keys = {"a", "b", "c", "d"};
+        std::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::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)