From af8e66d03b4366c7039a138306470567c2243130 Mon Sep 17 00:00:00 2001
From: Peter Dimov <pdimov@gmail.com>
Date: Sat, 27 Jan 2024 09:15:01 +0200
Subject: [PATCH] Replace operator safe_bool with explicit operator bool

---
 include/boost/function/function_template.hpp | 19 +------------------
 1 file changed, 1 insertion(+), 18 deletions(-)

diff --git a/include/boost/function/function_template.hpp b/include/boost/function/function_template.hpp
index f3a524f..3991e36 100644
--- a/include/boost/function/function_template.hpp
+++ b/include/boost/function/function_template.hpp
@@ -810,24 +810,7 @@ namespace boost {
       }
     }
 
-#if (defined __SUNPRO_CC) && (__SUNPRO_CC <= 0x530) && !(defined BOOST_NO_COMPILER_CONFIG)
-    // Sun C++ 5.3 can't handle the safe_bool idiom, so don't use it
-    operator bool () const { return !this->empty(); }
-#else
-  private:
-    struct dummy {
-      void nonnull() {}
-    };
-
-    typedef void (dummy::*safe_bool)();
-
-  public:
-    operator safe_bool () const
-      { return (this->empty())? 0 : &dummy::nonnull; }
-
-    bool operator!() const
-      { return this->empty(); }
-#endif
+    explicit operator bool () const { return !this->empty(); }
 
   private:
     void assign_to_own(const BOOST_FUNCTION_FUNCTION& f)