From 52502734fa80d8ed618746d9d40c3c53806fe445 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Sch=C3=A4pers?= <github@hazardy.de>
Date: Sun, 26 Jul 2026 10:21:53 +0200
Subject: [PATCH] Fix ODR violation in optional (#1522)

* Fix ODR violation in optional

Detected by GCC 15, when using in a module context.

* Make etl::nullopt constant
---
 include/etl/optional.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/etl/optional.h b/include/etl/optional.h
index 371c9f2a..eeb4b5c7 100644
--- a/include/etl/optional.h
+++ b/include/etl/optional.h
@@ -59,7 +59,7 @@ namespace etl
 
     // Convertible to any type of null non-member pointer.
     template <class T>
-    operator T*() const
+    ETL_CONSTEXPR operator T*() const ETL_NOEXCEPT
     {
       return 0;
     }
@@ -74,7 +74,7 @@ namespace etl
   /// A null option.
   ///\ingroup utilities
   //*****************************************************************************
-  const nullopt_t nullopt = {};
+  ETL_INLINE_VAR ETL_CONSTANT nullopt_t nullopt = {};
 
   //***************************************************************************
   /// Exception for optional.