fix universal: fix initialization of default values in FindOrDefault

Author: ddvamp

universal/include/userver/utils/algo.hpp

@@ -57,15 +57,17 @@ auto* FindOrNullptr(Container& container, const Key& key) {
 template <typename Container, typename Key, typename Default>
 auto FindOrDefault(Container& container, const Key& key, Default&& def) {
     const auto* ptr = USERVER_NAMESPACE::utils::FindOrNullptr(container, key);
-    return (ptr ? *ptr : decltype(*ptr){std::forward<Default>(def)});
+    using R = std::remove_cvref_t<decltype(*ptr)>;
+    return (ptr ? *ptr : R(std::forward<Default>(def)));
 }
 
 /// @brief Returns default value if no key in associative container, otherwise
 /// returns a copy of the stored value.
 template <typename Container, typename Key>
 auto FindOrDefault(Container& container, const Key& key) {
     const auto* ptr = USERVER_NAMESPACE::utils::FindOrNullptr(container, key);
-    return (ptr ? *ptr : decltype(*ptr){});
+    using R = std::remove_cvref_t<decltype(*ptr)>;
+    return (ptr ? *ptr : R());
 }
 
 /// @brief Returns std::nullopt if no key in associative container, otherwise

universal/src/utils/algo_test.cpp

@@ -48,21 +48,26 @@ TEST(UtilsAlgo, FindOrNullptrSets) {
 
 TEST(UtilsAlgo, FindOrDefaultMaps) {
     constexpr int kFallback = 42;
+    constexpr int kDefault = int();
     std::map<std::string, int> m = {{"1", 2}};
     std::unordered_map<std::string, int> um = {{"1", 2}};
 
     EXPECT_EQ(utils::FindOrDefault(m, "2", kFallback), kFallback);
     EXPECT_EQ(utils::FindOrDefault(um, "2", kFallback), kFallback);
 
-    ASSERT_EQ(utils::FindOrDefault(m, "1", kFallback), 2);
-    ASSERT_EQ(utils::FindOrDefault(um, "1", kFallback), 2);
-
     EXPECT_EQ(utils::FindOrDefault(m, "1", kFallback), 2);
     EXPECT_EQ(utils::FindOrDefault(um, "1", kFallback), 2);
+
+    EXPECT_EQ(utils::FindOrDefault(m, "2"), kDefault);
+    EXPECT_EQ(utils::FindOrDefault(um, "2"), kDefault);
+
+    EXPECT_EQ(utils::FindOrDefault(m, "1"), 2);
+    EXPECT_EQ(utils::FindOrDefault(um, "1"), 2);
 }
 
 TEST(UtilsAlgo, FindOrDefaultSets) {
     constexpr int kFallback = 42;
+    constexpr int kDefault = int();
     std::set<int> s = {1};
     std::unordered_set<int> us = {1};
 
@@ -71,6 +76,12 @@ TEST(UtilsAlgo, FindOrDefaultSets) {
 
     EXPECT_EQ(utils::FindOrDefault(s, 1, kFallback), 1);
     EXPECT_EQ(utils::FindOrDefault(us, 1, kFallback), 1);
+
+    EXPECT_EQ(utils::FindOrDefault(s, 2), kDefault);
+    EXPECT_EQ(utils::FindOrDefault(us, 2), kDefault);
+
+    EXPECT_EQ(utils::FindOrDefault(s, 1), 1);
+    EXPECT_EQ(utils::FindOrDefault(us, 1), 1);
 }
 
 TEST(UtilsAlgo, FindOptionalMaps) {