From b9d5b6d0b027fc365d084c952f0fc0be23585511 Mon Sep 17 00:00:00 2001
From: Boris Zbarsky <bzbarsky@apple.com>
Date: Tue, 10 Nov 2020 23:38:42 -0500
Subject: [PATCH] Add a ValueOr method to Optional

This allows easier use of the "the value in the Optional or this
default value I have" pattern.
---
 src/lib/core/Optional.h                | 11 +++++++++++
 src/protocols/echo/EchoClient.cpp      |  3 +--
 src/transport/SecurePairingSession.cpp |  4 ++--
 3 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/src/lib/core/Optional.h b/src/lib/core/Optional.h
index 380c3bf10bd2a3..d49ed49d88fcf6 100644
--- a/src/lib/core/Optional.h
+++ b/src/lib/core/Optional.h
@@ -59,6 +59,17 @@ class Optional
         return mValue;
     }
 
+    /** Gets the current value of the optional if the optional has a value;
+        otherwise returns the provided default value. */
+    const T & ValueOr(const T & defaultValue) const
+    {
+        if (HasValue())
+        {
+            return mValue;
+        }
+        return defaultValue;
+    }
+
     /** Checks if the optional contains a value or not */
     bool HasValue() const { return mHasValue; }
 
diff --git a/src/protocols/echo/EchoClient.cpp b/src/protocols/echo/EchoClient.cpp
index 1731a7c215cf21..33de0f00104b93 100644
--- a/src/protocols/echo/EchoClient.cpp
+++ b/src/protocols/echo/EchoClient.cpp
@@ -117,8 +117,7 @@ void EchoClient::OnMessageReceived(ExchangeContext * ec, const PacketHeader & pa
     // Call the registered OnEchoResponseReceived handler, if any.
     if (echoApp->OnEchoResponseReceived != nullptr)
     {
-        echoApp->OnEchoResponseReceived(packetHeader.GetSourceNodeId().HasValue() ? packetHeader.GetSourceNodeId().Value() : 0,
-                                        payload);
+        echoApp->OnEchoResponseReceived(packetHeader.GetSourceNodeId().ValueOr(0), payload);
     }
 
 exit:
diff --git a/src/transport/SecurePairingSession.cpp b/src/transport/SecurePairingSession.cpp
index 780654bd82676d..c46c392b1cfbbe 100644
--- a/src/transport/SecurePairingSession.cpp
+++ b/src/transport/SecurePairingSession.cpp
@@ -104,8 +104,8 @@ CHIP_ERROR SecurePairingSession::ToSerializable(SecurePairingSessionSerializable
 {
     CHIP_ERROR error = CHIP_NO_ERROR;
 
-    const NodeId localNodeId = (mLocalNodeId.HasValue()) ? mLocalNodeId.Value() : kUndefinedNodeId;
-    const NodeId peerNodeId  = (mPeerNodeId.HasValue()) ? mPeerNodeId.Value() : kUndefinedNodeId;
+    const NodeId localNodeId = mLocalNodeId.ValueOr(kUndefinedNodeId);
+    const NodeId peerNodeId  = mPeerNodeId.ValueOr(kUndefinedNodeId);
     VerifyOrExit(CanCastTo<uint16_t>(mKeLen), error = CHIP_ERROR_INTERNAL);
     VerifyOrExit(CanCastTo<uint64_t>(localNodeId), error = CHIP_ERROR_INTERNAL);
     VerifyOrExit(CanCastTo<uint64_t>(peerNodeId), error = CHIP_ERROR_INTERNAL);