From fbf58139f735ca9fb5a7e933204234c374f7fb47 Mon Sep 17 00:00:00 2001
From: Anton Kolesnyk <41349689+antkmsft@users.noreply.github.com>
Date: Tue, 28 Nov 2023 00:10:52 -0800
Subject: [PATCH] Nullable::Emplace() to set HasValue() (#5178)

Co-authored-by: Anton Kolesnyk <antkmsft@users.noreply.github.com>
---
 sdk/core/azure-core/CHANGELOG.md              |  1 +
 .../azure-core/inc/azure/core/nullable.hpp    |  1 +
 sdk/core/azure-core/test/ut/nullable_test.cpp | 28 +++++++++++++++++++
 3 files changed, 30 insertions(+)

diff --git a/sdk/core/azure-core/CHANGELOG.md b/sdk/core/azure-core/CHANGELOG.md
index 1fb18874e..be3b2d465 100644
--- a/sdk/core/azure-core/CHANGELOG.md
+++ b/sdk/core/azure-core/CHANGELOG.md
@@ -8,6 +8,7 @@
 
 ### Bugs Fixed
 
+- [[#5172]](https://github.com/Azure/azure-sdk-for-cpp/issues/5172) `Azure::Nullable::Emplace()` does not set `HasValue()` to `true`.
 - [[#5130]](https://github.com/Azure/azure-sdk-for-cpp/issues/5130) `Url::AppendPath()` and `Url::SetPath()` may end up with a double slash at the beginning of a path.
 
 ### Other Changes
diff --git a/sdk/core/azure-core/inc/azure/core/nullable.hpp b/sdk/core/azure-core/inc/azure/core/nullable.hpp
index 13584e8b9..5111d8aa8 100644
--- a/sdk/core/azure-core/inc/azure/core/nullable.hpp
+++ b/sdk/core/azure-core/inc/azure/core/nullable.hpp
@@ -218,6 +218,7 @@ public:
   {
     Reset();
     ::new (static_cast<void*>(&m_value)) T(std::forward<U>(Args)...);
+    m_hasValue = true;
     return m_value;
   }
 
diff --git a/sdk/core/azure-core/test/ut/nullable_test.cpp b/sdk/core/azure-core/test/ut/nullable_test.cpp
index 16911c6b6..b25ec791f 100644
--- a/sdk/core/azure-core/test/ut/nullable_test.cpp
+++ b/sdk/core/azure-core/test/ut/nullable_test.cpp
@@ -99,6 +99,34 @@ TEST(Nullable, ValueAssignment)
   EXPECT_FALSE(strVal.HasValue());
 }
 
+TEST(Nullable, Emplace)
+{
+  {
+    Azure::Nullable<int> x;
+    EXPECT_FALSE(x.HasValue());
+    EXPECT_EQ(x.Emplace(42), 42);
+    EXPECT_TRUE(x.HasValue());
+    EXPECT_EQ(x.Value(), 42);
+  }
+
+  {
+    Azure::Nullable<int> y;
+    EXPECT_FALSE(y.HasValue());
+    EXPECT_EQ(y.Emplace(), 0);
+    EXPECT_TRUE(y.HasValue());
+    EXPECT_EQ(y.Value(), 0);
+  }
+
+  {
+    Azure::Nullable<int> z = 42;
+    EXPECT_TRUE(z.HasValue());
+    EXPECT_EQ(z.Value(), 42);
+    EXPECT_EQ(z.Emplace(), 0);
+    EXPECT_TRUE(z.HasValue());
+    EXPECT_EQ(z.Value(), 0);
+  }
+}
+
 TEST(Nullable, Swap)
 {
   Nullable<int> val1;