feat add optional to namespace ulib

3party/optional/optional.h

@@ -2495,4 +2495,42 @@ constexpr tl::nullopt_t nullopt{tl::nullopt};
 
 }// namespace std
 
+namespace ulib {
+template<typename T>
+using hash = std::hash<tl::optional<T>>;
+
+// if <= C++14
+#if __cplusplus < 201703L
+template<typename T>
+using optional = tl::optional<T>;
+
+template<typename T>
+using nullopt_t = tl::nullopt_t;
+
+// make_optional
+template<typename T>
+constexpr tl::optional<tl::detail::decay_t<T>>
+make_optional(T &&v)
+{
+    return tl::make_optional(std::forward<T>(v));
+}
+
+template<typename T, typename... Args>
+constexpr tl::optional<T>
+make_optional(Args &&...args)
+{
+    return tl::make_optional<T>(std::forward<Args>(args)...);
+}
+
+template<typename T, typename U, typename... Args>
+constexpr tl::optional<T>
+make_optional(std::initializer_list<U> il, Args &&...args)
+{
+    return tl::make_optional<T>(il, std::forward<Args>(args)...);
+}
+
+constexpr tl::nullopt_t nullopt{tl::nullopt};
+#endif
+
+}// namespace ulib
 #endif

tests/3party/optional/optional_unittest.cpp

@@ -0,0 +1,19 @@
+#include <gtest/gtest.h>
+#include <optional.h>
+
+TEST(optional, has_value)
+{
+    ulib::optional<int> int_opt = 1;
+    EXPECT_TRUE(int_opt.has_value());
+    EXPECT_EQ(*int_opt, 1);
+    EXPECT_EQ(int_opt.value(), 1);
+    EXPECT_EQ(int_opt.value_or(2), 1);
+}
+
+TEST(optional, not_has_value)
+{
+    ulib::optional<int> int_opt;
+    EXPECT_FALSE(int_opt.has_value());
+    EXPECT_EQ(int_opt.value_or(1), 1);
+    EXPECT_EQ(int_opt.value_or(2), 2);
+}

tests/CMakeLists.txt

@@ -13,6 +13,7 @@ add_executable(ulib_test
         ulib/system/thread_pool_unittest.cpp
         ulib/system/timer_unittest.cpp
         3party/inja/inja_unittest.cpp
+        3party/optional/optional_unittest.cpp
         ulib/utils/defer_unittest.cpp
 )
 target_link_libraries(ulib_test PRIVATE