From: Nicholas Ormrod <njormrod@fb.com>
Date: Mon, 12 May 2014 18:02:00 +0000 (-0700)
Subject: small_vector exception safety, part 2
X-Git-Tag: v0.22.0~543
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=278a1f7dbb4c8f938114cf550c0a07bcdda11161;p=folly.git

small_vector exception safety, part 2

Summary:
small_vector is now object-exception safe for all container
functions, except for input-iterators.

That's a bold claim; probably incorrect. At the very least, it passes
the same test suite as std::vector and fbvector.

Aside: Clearly, no one uses erase(q1, q2) in the wild.

Facebook: Nothing special.

Test Plan:
fbconfig -r folly && fbmake runtests
fbconfig -r experimental/njormrod/stltest && fbmake runtests

Reviewed By: andrei.alexandrescu@fb.com

FB internal diff: D1319787
---

diff --git a/folly/small_vector.h b/folly/small_vector.h
index c33eb745..f5eddcb3 100644
--- a/folly/small_vector.h
+++ b/folly/small_vector.h
@@ -737,8 +737,9 @@ public:
   }
 
   iterator erase(const_iterator q1, const_iterator q2) {
+    if (q1 == q2) return unconst(q1);
     std::move(unconst(q2), end(), unconst(q1));
-    for (auto it = q1; it != end(); ++it) {
+    for (auto it = (end() - std::distance(q1, q2)); it != end(); ++it) {
       it->~value_type();
     }
     this->setSize(size() - (q2 - q1));