Solved: 44 - Ranges

modules/12_cpp20/src/ranges.cpp

@@ -3,18 +3,18 @@
 namespace cpp20 {
 
 auto even_numbers(const std::vector<int>& input) -> std::vector<int> {
-    (void)input;
-    return {};
+    return std::ranges::filter_view(input, [](auto x) { return x % 2 == 0; })
+        | std::ranges::to<std::vector<int>>();
 }
 
 auto take_first_three(const std::vector<int>& input) -> std::vector<int> {
-    (void)input;
-    return {};
+    return std::ranges::take_view(input, 3)
+        | std::ranges::to<std::vector<int>>();
 }
 
 auto join_strings(const std::vector<std::string>& parts) -> std::string {
-    (void)parts;
-    return {};
+    return std::ranges::join_view(parts)
+        | std::ranges::to<std::string>();
 }
 
 }  // namespace cpp20