Add a ZeroingAllocator::rebind<Other> for Other==char
Newer versions of libc++ check that an allocator can be rebound to the
same element type. We need to add a rebind member to ZeroingAllocator
to fix this compiler error:
prebuilts/clang/host/linux-x86/clang-r498229/include/c++/v1/vector:376:19: error: static assertion failed due to requirement 'is_same<android::vold::ZeroingAllocator, std::allocator<char>>::value': [allocator.requirements] states that rebinding an allocator to the same type should result in the original allocator
static_assert(is_same<allocator_type, __rebind_alloc<__alloc_traits, value_type> >::value,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
It likely doesn't matter in practice because this allocator is only
used with std::vector, which probably doesn't use allocator rebinding,
because it won't allocate an internal node type (e.g. unlike std::map,
std::list, etc).
Alternatively, ZeroingAllocator could be changed to a
ZeroingAllocator<T> that can zero arbitrary types, but it doesn't seem
necessary currently, and types other than char wouldn't be used.
Bug: b/175635923
Test: treehugger
Change-Id: I42e9d8f02a18637fc67e94cc1358d2ed733a7268
diff --git a/KeyBuffer.h b/KeyBuffer.h
index 4468220..3275255 100644
--- a/KeyBuffer.h
+++ b/KeyBuffer.h
@@ -19,6 +19,7 @@
#include <string.h>
#include <memory>
+#include <type_traits>
#include <vector>
namespace android {
@@ -31,6 +32,12 @@
memset_explicit(p, 0, n);
std::allocator<char>::deallocate(p, n);
}
+
+ template <class Other>
+ struct rebind {
+ static_assert(std::is_same_v<char, Other>, "ZeroingAllocator is only defined for char");
+ using other = ZeroingAllocator;
+ };
};
// Char vector that zeroes memory when deallocating.