From cc7b7d991b59b29a7a46b0b6adba7933a2c59cc5 Mon Sep 17 00:00:00 2001
From: Jonathan Hui <jonhui@google.com>
Date: Mon, 3 May 2021 22:51:11 -0700
Subject: [PATCH] [routing-manager] add message to static_assert (#6560)

static_assert with no message is a C++17 extension.
---
 src/core/border_router/routing_manager.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/core/border_router/routing_manager.cpp b/src/core/border_router/routing_manager.cpp
index 128854418..1e8765a91 100644
--- a/src/core/border_router/routing_manager.cpp
+++ b/src/core/border_router/routing_manager.cpp
@@ -658,7 +658,7 @@ void RoutingManager::SendRouterAdvertisement(const Ip6::Prefix *aNewOmrPrefixes,
     uint8_t  buffer[kMaxRouterAdvMessageLength];
     uint16_t bufferLength = 0;
 
-    static_assert(sizeof(mRouterAdvMessage) <= sizeof(buffer));
+    static_assert(sizeof(mRouterAdvMessage) <= sizeof(buffer), "RA buffer too small");
     memcpy(buffer, &mRouterAdvMessage, sizeof(mRouterAdvMessage));
     bufferLength += sizeof(mRouterAdvMessage);