From e3df05b15a24682fcff2b1e5c149678c3501d98a Mon Sep 17 00:00:00 2001
From: KRM7 <70973547+KRM7@users.noreply.github.com>
Date: Wed, 7 Feb 2024 19:46:32 +0100
Subject: [PATCH] add static_assert for completeness (closes #2)

---
 src/small_unique_ptr.hpp | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/small_unique_ptr.hpp b/src/small_unique_ptr.hpp
index b4c3d5e..079f1c7 100644
--- a/src/small_unique_ptr.hpp
+++ b/src/small_unique_ptr.hpp
@@ -55,6 +55,16 @@ namespace detail
     inline constexpr bool is_proper_base_of_v = is_proper_base_of<Base, Derived>::value;
 
 
+    template<typename T, typename = void>
+    struct is_complete : std::false_type {};
+
+    template<typename T>
+    struct is_complete<T, std::void_t<decltype(sizeof(T))>> {};
+
+    template<typename T>
+    inline constexpr bool is_complete_v = is_complete<T>::value;
+
+
     inline constexpr std::size_t small_ptr_size = 64;
 
 
@@ -203,7 +213,7 @@ template<typename T>
 class small_unique_ptr : private detail::small_unique_ptr_base<T>
 {
 public:
-    static_assert(!std::is_array_v<T> && !std::is_void_v<T>);
+    static_assert(detail::is_complete_v<T> && !std::is_array_v<T>);
 
     using element_type = T;
     using pointer      = T*;