[gcc r10-9573] libstdc++: Avoid narrowing conversion in subrange constructor

[Jonathan Wakely]

https://gcc.gnu.org/g:4ab3d8aca1f377a4cbc94316770e629462ff8bbd

commit r10-9573-g4ab3d8aca1f377a4cbc94316770e629462ff8bbd
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Thu Oct 29 22:47:22 2020 +0000

    libstdc++: Avoid narrowing conversion in subrange constructor
    
    libstdc++-v3/ChangeLog:
    
            * include/std/ranges (subrange::subrange(R&&)): Use
            direct-initialization instead of list-initialization, so a
            potential narrowing conversion from ranges::size(r) to the
            stored size isn't ill-formed.
    
    (cherry picked from commit a55cda891d69b5a238d2e237903829995ca7249c)

Diff:
---
 libstdc++-v3/include/std/ranges | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges
index 8d3b662f928..78dacbe5ec7 100644
--- a/libstdc++-v3/include/std/ranges
+++ b/libstdc++-v3/include/std/ranges
@@ -282,7 +282,7 @@ namespace ranges
 	  && convertible_to<sentinel_t<_Rng>, _Sent>
 	constexpr
 	subrange(_Rng&& __r) requires _S_store_size && sized_range<_Rng>
-	: subrange{__r, ranges::size(__r)}
+	: subrange(__r, ranges::size(__r))
 	{ }
 
       template<__detail::__not_same_as<subrange> _Rng>