Fix UBSAN failure in RangeTest.cpp with libstdc++-v4.9

Summary:
[Folly] Fix UBSAN failure in `RangeTest.cpp` with `libstdc++-v4.9`.

The implementation of `std::array` in `libstdc++-v4.9` has undefined behavior in the case of the zero-length array - dereferencing (but immediately taking the address again) of `nullptr`. This is fixed in `libstdc++-v5`.

Reviewed By: ot

Differential Revision: D6528614

fbshipit-source-id: 26be6bdc28d9e6dc6e6293a4d4ecffd769c01413

diff --git a/folly/test/RangeTest.cpp b/folly/test/RangeTest.cpp
index dbe8d88fa2b6fa216c8207696127138ddcd413c4..b1298cacec7f659466ce85bdd9f990d169bd9338 100644 (file)
--- a/folly/test/RangeTest.cpp
+++ b/folly/test/RangeTest.cpp
@@ -1201,7 +1201,7 @@ TEST(CRangeFunc, StdArrayZero) {
   auto const numArrayRange = crange(numArray);
   EXPECT_TRUE(
       (std::is_same<int const*, decltype(numArrayRange)::iterator>::value));
   auto const numArrayRange = crange(numArray);
   EXPECT_TRUE(
       (std::is_same<int const*, decltype(numArrayRange)::iterator>::value));

-  EXPECT_THAT(numArrayRange, testing::ElementsAreArray(numArray));
+  EXPECT_THAT(numArrayRange, testing::IsEmpty());

 }
 
 TEST(CRangeFunc, Collection) {
 }
 
 TEST(CRangeFunc, Collection) {