From cb7ca96f688fc239cd060b359e93c9a0bb342950 Mon Sep 17 00:00:00 2001
From: Howard Hinnant <howard.hinnant@gmail.com>
Date: Tue, 19 Mar 2019 19:51:32 -0400
Subject: [PATCH] Protect weekday_from_days from signed overflow Found by
 static analyzer. This change makes weekday_from_days slightly more efficient.

---
 include/date/date.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/date/date.h b/include/date/date.h
index 318dfca..5938c4e 100644
--- a/include/date/date.h
+++ b/include/date/date.h
@@ -1719,8 +1719,8 @@ inline
 unsigned char
 weekday::weekday_from_days(int z) NOEXCEPT
 {
-    return static_cast<unsigned char>(static_cast<unsigned>(
-        z >= -4 ? (z+4) % 7 : (z+5) % 7 + 6));
+    auto u = static_cast<unsigned>(z);
+    return static_cast<unsigned char>(z >= -4 ? (u+4) % 7 : u % 7);
 }
 
 CONSTCD11