diff --git a/src/small_unique_ptr.hpp b/src/small_unique_ptr.hpp
index cb6eb9f..28292eb 100644
--- a/src/small_unique_ptr.hpp
+++ b/src/small_unique_ptr.hpp
@@ -1,10 +1,12 @@
 /* Copyright (c) 2024 Krisztián Rugási. Subject to the MIT License. */
 
-#ifndef SMALL_UNIQUE_PTR_SMALL_UNIQUE_PTR_HPP
-#define SMALL_UNIQUE_PTR_SMALL_UNIQUE_PTR_HPP
+#ifndef SMALL_UNIQUE_PTR_HPP
+#define SMALL_UNIQUE_PTR_HPP
 
 #include <compare>
 #include <memory>
+#include <iosfwd>
+#include <functional>
 #include <new>
 #include <type_traits>
 #include <utility>
@@ -288,6 +290,18 @@ class small_unique_ptr : private detail::small_unique_ptr_base<T>
         }
     }
 
+    [[nodiscard]]
+    constexpr static bool is_always_heap_allocated() noexcept
+    {
+        return detail::always_heap_allocated_v<T>;
+    }
+
+    [[nodiscard]]
+    constexpr bool is_stack_allocated() const noexcept
+    {
+        return small_unique_ptr_base::is_stack_allocated();
+    }
+
     [[nodiscard]]
     constexpr pointer get() const noexcept
     {
@@ -336,6 +350,12 @@ class small_unique_ptr : private detail::small_unique_ptr_base<T>
         return this->data_ <=> rhs.data_;
     }
 
+    template<typename CharT, typename Traits>
+    friend std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>& os, const small_unique_ptr& p)
+    {
+        return os << p.get();
+    }
+
 private:
     template<typename B = T>
     constexpr std::ptrdiff_t offsetof_base() const noexcept
@@ -362,6 +382,19 @@ constexpr void swap(small_unique_ptr<T>& lhs, small_unique_ptr<T>& rhs) noexcept
     lhs.swap(rhs);
 }
 
+namespace std
+{
+    template<typename T>
+    struct hash<small_unique_ptr<T>>
+    {
+        std::size_t operator()(const small_unique_ptr<T>& p) const noexcept
+        {
+            return std::hash<typename small_unique_ptr<T>::pointer>{}(p.get());
+        }
+    };
+
+} // namespace std
+
 template<typename T, typename... Args>
 [[nodiscard]] constexpr small_unique_ptr<T> make_unique_small(Args&&... args)
 noexcept(!detail::always_heap_allocated_v<T> && std::is_nothrow_constructible_v<T, Args...>)
@@ -385,4 +418,4 @@ noexcept(!detail::always_heap_allocated_v<T> && std::is_nothrow_constructible_v<
     return ptr;
 }
 
-#endif // !SMALL_UNIQUE_PTR_SMALL_UNIQUE_PTR_HPP
\ No newline at end of file
+#endif // !SMALL_UNIQUE_PTR_HPP
\ No newline at end of file
diff --git a/test/small_unique_ptr.cpp b/test/small_unique_ptr.cpp
index 939674b..100004d 100644
--- a/test/small_unique_ptr.cpp
+++ b/test/small_unique_ptr.cpp
@@ -71,6 +71,36 @@ TEST_CASE("construction", "[small_unique_ptr]")
     REQUIRE_NOTHROW(make_unique_small<LargePOD>());
 }
 
+TEST_CASE("is_always_heap_allocated", "[small_unique_ptr]")
+{
+    STATIC_REQUIRE(!small_unique_ptr<SmallDerived>::is_always_heap_allocated());
+    STATIC_REQUIRE(small_unique_ptr<LargeDerived>::is_always_heap_allocated());
+
+    STATIC_REQUIRE(!small_unique_ptr<SmallPOD>::is_always_heap_allocated());
+    STATIC_REQUIRE(small_unique_ptr<LargePOD>::is_always_heap_allocated());
+}
+
+TEST_CASE("is_stack_allocated", "[small_unique_ptr]")
+{
+    STATIC_REQUIRE( !std::invoke([]{ return make_unique_small<SmallDerived>().is_stack_allocated(); }) );
+    STATIC_REQUIRE( !std::invoke([]{ return make_unique_small<LargeDerived>().is_stack_allocated(); }) );
+
+    STATIC_REQUIRE( !std::invoke([]{ return make_unique_small<SmallPOD>().is_stack_allocated(); }) );
+    STATIC_REQUIRE( !std::invoke([]{ return make_unique_small<LargePOD>().is_stack_allocated(); }) );
+
+    small_unique_ptr<Base> p1 = make_unique_small<SmallDerived>();
+    small_unique_ptr<Base> p2 = make_unique_small<LargeDerived>();
+
+    REQUIRE(p1.is_stack_allocated());
+    REQUIRE(!p2.is_stack_allocated());
+
+    small_unique_ptr<SmallPOD> p3 = make_unique_small<SmallPOD>();
+    small_unique_ptr<LargePOD> p4 = make_unique_small<LargePOD>();
+
+    REQUIRE(p3.is_stack_allocated());
+    REQUIRE(!p4.is_stack_allocated());
+}
+
 TEST_CASE("comparisons", "[small_unique_ptr]")
 {
     STATIC_REQUIRE(small_unique_ptr<SmallPOD>(nullptr) == nullptr);
@@ -423,7 +453,6 @@ TEST_CASE("poly_alignment", "[small_unique_ptr]")
 TEST_CASE("const_unique_ptr", "[small_unique_ptr]")
 {
     const small_unique_ptr<int> p = make_unique_small<int>(3);
-
     *p = 2;
 
     REQUIRE(*p == 2);