5 files changed, 85 insertions, 2 deletions
diff --git a/test/include/hash_suite.hpp b/test/include/hash_suite.hpp
new file mode 100644
index 0000000..0ef51bc
--- /dev/null
+++ b/test/include/hash_suite.hpp
@@ -0,0 +1,11 @@
+#ifndef NEWTYPE_TEST_HASH_SUITE_HPP
+#define NEWTYPE_TEST_HASH_SUITE_HPP
+
+#include <cute/cute_suite.h>
+
+#include <string>
+#include <utility>
+
+auto hash_suite() -> std::pair<cute::suite, std::string>;
+
+#endif
+\ No newline at end of file
diff --git a/test/include/kawaii.hpp b/test/include/kawaii.hpp
index 69da012..9084b56 100644
--- a/test/include/kawaii.hpp
+++ b/test/include/kawaii.hpp
@@ -18,7 +18,7 @@ namespace nt::test
   {
     auto constexpr prepositions = std::array{"a", "an", "and", "as", "at", "by", "for", "in", "of", "on", "or", "the", "to"};
     auto constexpr keywords = std::array{"noexcept"};
-    auto constexpr type_names = std::array{"new_type", "derivation_clause"};
+    auto constexpr type_names = std::array{"new_type", "derivation_clause", "unordered_map"};
 
     auto inline replace_template_argument_syntax(std::string const & name) -> std::string
     {
diff --git a/test/src/arithmetic_suite.cpp b/test/src/arithmetic_suite.cpp
index f831b98..2e7f1fd 100644
--- a/test/src/arithmetic_suite.cpp
+++ b/test/src/arithmetic_suite.cpp
@@ -1,4 +1,5 @@
-#include "conversion_suite.hpp"
+#include "arithmetic_suite.hpp"
+
 #include "kawaii.hpp"
 #include "newtype/derivable.hpp"
 #include "newtype/deriving.hpp"
diff --git a/test/src/driver.cpp b/test/src/driver.cpp
index c93f157..cfd6b90 100644
--- a/test/src/driver.cpp
+++ b/test/src/driver.cpp
@@ -2,6 +2,7 @@
 #include "conversion_suite.hpp"
 #include "derivation_clause_suite.hpp"
 #include "equality_comparison_suite.hpp"
+#include "hash_suite.hpp"
 #include "io_operators_suite.hpp"
 #include "new_type_constructor_suite.hpp"
 #include "relational_operators_suite.hpp"
@@ -59,6 +60,7 @@ int main(int argc, char ** argv)
       relational_operators_suite(),
       io_operators_suite(),
       arithmetic_suite(),
+      hash_suite(),
   };
 
   auto selectors = get_test_selectors(suites);
diff --git a/test/src/hash_suite.cpp b/test/src/hash_suite.cpp
new file mode 100644
index 0000000..9ca362c
--- /dev/null
+++ b/test/src/hash_suite.cpp
@@ -0,0 +1,69 @@
+#include "hash_suite.hpp"
+
+#include "kawaii.hpp"
+#include "newtype/derivable.hpp"
+#include "newtype/deriving.hpp"
+#include "newtype/impl/type_traits_extensions.hpp"
+#include "newtype/new_type.hpp"
+
+#include <cute/cute.h>
+
+#include <unordered_map>
+
+inline namespace hashable_tests
+{
+
+  auto a_new__type_that_does_not_include_hash_in_its_derivation_clause_is_not_hashable() -> void
+  {
+    using type_alias = nt::new_type<int, struct tag>;
+    ASSERT(!nt::impl::is_hashable_v<type_alias>);
+  }
+
+  auto a_new__type_that_does_include_hash_in_its_derivation_clause_is_hashable() -> void
+  {
+    static_assert(nt::impl::is_hashable_v<int>, "Sanity Check");
+    using type_alias = nt::new_type<int, struct tag, deriving(nt::Hash)>;
+    ASSERT(nt::impl::is_hashable_v<type_alias>);
+  }
+
+  auto a_new__type_that_does_include_hash_in_its_derivation_clause_but_whose_base_type_is_not_hashable_is_also_not_hashable() -> void
+  {
+    struct not_hashable
+    {
+    };
+
+    static_assert(!nt::impl::is_hashable_v<not_hashable>, "Sanity Check");
+    using type_alias = nt::new_type<not_hashable, struct tag, deriving(nt::Hash)>;
+    ASSERT(!nt::impl::is_hashable_v<type_alias>);
+  }
+
+}  // namespace hashable_tests
+
+inline namespace usage_tests
+{
+
+  auto a_new__type_that_is_hashable_can_be_used_in_an_unordered__map() -> void
+  {
+    static_assert(nt::impl::is_hashable_v<int>, "Sanity Check");
+    using type_alias = nt::new_type<int, struct tag, deriving(nt::Hash)>;
+
+    auto map = std::unordered_map<type_alias, int>{};
+    map[type_alias{42}] = 43;
+    ASSERT_EQUAL(43, map[type_alias{42}]);
+  }
+
+}  // namespace usage_tests
+
+auto hash_suite() -> std::pair<cute::suite, std::string>
+{
+  return {{
+              // Hashable Tests
+              KAWAII(a_new__type_that_does_not_include_hash_in_its_derivation_clause_is_not_hashable),
+              KAWAII(a_new__type_that_does_include_hash_in_its_derivation_clause_is_hashable),
+              KAWAII(a_new__type_that_does_include_hash_in_its_derivation_clause_but_whose_base_type_is_not_hashable_is_also_not_hashable),
+
+              // Usage Tests
+              KAWAII(a_new__type_that_is_hashable_can_be_used_in_an_unordered__map),
+          },
+          "std::hash Support Tests"};
+}
+\ No newline at end of file