From 54c841d585e2cda007a2936af252a6cb43ef1050 Mon Sep 17 00:00:00 2001
From: Gennaro Prota <gennaro.prota@gmail.com>
Date: Mon, 22 Dec 2025 11:53:06 +0100
Subject: [PATCH] Exercise subtraction between iterators in the unit tests

Reason: This was missing. And we forgot a friend declaration for the
corresponding operator-(), which will be added with the next commit.
---
 test/bitset_test.hpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/test/bitset_test.hpp b/test/bitset_test.hpp
index 29f884f..3fb18a8 100644
--- a/test/bitset_test.hpp
+++ b/test/bitset_test.hpp
@@ -248,6 +248,8 @@ struct bitset_test
             BOOST_TEST( *( 1 + b.begin() ) == b[ 1 ] );
             BOOST_TEST( *( b.end() - 1 ) == b[ b.size() - 1 ] );
         }
+
+        BOOST_TEST( b.end() - b.begin() == static_cast< std::ptrdiff_t >( b.size() ) );
     }
 
     static void