From 51d88b2314054ad686b1334625985a509e2f94a7 Mon Sep 17 00:00:00 2001
From: Ole Erik Peistorpet <OleErikPeistorpet@users.noreply.github.com>
Date: Thu, 30 May 2024 18:46:28 +0200
Subject: [PATCH] static_assert in _detail::Size

---
 auxi/range_traits.h | 4 +++-
 util.h              | 5 +++--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/auxi/range_traits.h b/auxi/range_traits.h
index a787e3d7..a6df2cb9 100644
--- a/auxi/range_traits.h
+++ b/auxi/range_traits.h
@@ -139,7 +139,9 @@ namespace _detail
 	>
 	constexpr auto Size(Range && r, None...)
 	->	decltype(end(r) - begin(r))
-	{	return   end(r) - begin(r); }
+	{	return   end(r) - begin(r);
+		static_assert(std::is_copy_constructible_v< iterator_t<Range> > or !std::is_lvalue_reference_v<Range>);
+	}
 }
 
 } // oel
diff --git a/util.h b/util.h
index f6e1b0c2..cf6fdfda 100644
--- a/util.h
+++ b/util.h
@@ -53,9 +53,10 @@ inline constexpr auto as_unsigned =
 * Ill-formed if `r.size()` is ill-formed and `begin(r)` cannot be subtracted from `end(r)` (SFINAE-friendly) */
 template< typename SizedRangeLike >
 constexpr auto ssize(SizedRangeLike && r)
-->	std::common_type_t< ptrdiff_t, decltype(as_signed( _detail::Size(r) )) >
+->	std::common_type_t<ptrdiff_t, decltype( as_signed(_detail::Size(r)) )>
 	{
-		return std::common_type_t< ptrdiff_t, decltype(as_signed( _detail::Size(r) )) >(_detail::Size(r));
+		return std::common_type_t<ptrdiff_t, decltype( as_signed(_detail::Size(r)) )>
+			(_detail::Size( static_cast<SizedRangeLike &&>(r) ));
 	}
 
 namespace view