Implement P0513R0 - "Poisoning the Hash"
Summary:
Exactly what the title says.
This patch also adds a `std::hash<nullptr_t>` specialization in C++17, but it was not added by this paper and I can't find the actual paper that adds it.
See http://wg21.link/P0513R0 for more info.
If there are no comments in the next couple of days I'll commit this
Reviewers: mclow.lists, K-ballo, EricWF
Reviewed By: EricWF
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D28938
llvm-svn: 292684
diff --git a/libcxx/test/std/utilities/optional/optional.hash/hash.pass.cpp b/libcxx/test/std/utilities/optional/optional.hash/hash.pass.cpp
index dfdd07d..ea89dc3 100644
--- a/libcxx/test/std/utilities/optional/optional.hash/hash.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.hash/hash.pass.cpp
@@ -17,6 +17,15 @@
#include <memory>
#include <cassert>
+#include "poisoned_hash_helper.hpp"
+
+struct A {};
+struct B {};
+
+template <>
+struct std::hash<B> {
+ size_t operator()(B const&) { return 0; }
+};
int main()
{
@@ -45,4 +54,16 @@
opt = std::unique_ptr<int>(new int(3));
assert(std::hash<optional<T>>{}(opt) == std::hash<T>{}(*opt));
}
+ {
+ test_hash_enabled_for_type<std::optional<int> >();
+ test_hash_enabled_for_type<std::optional<int*> >();
+ test_hash_enabled_for_type<std::optional<const int> >();
+ test_hash_enabled_for_type<std::optional<int* const> >();
+
+ test_hash_disabled_for_type<std::optional<A>>();
+ test_hash_disabled_for_type<std::optional<const A>>();
+
+ test_hash_enabled_for_type<std::optional<B>>();
+ test_hash_enabled_for_type<std::optional<const B>>();
+ }
}