4 files changed, 33 insertions, 22 deletions
diff --git a/compat/borrowed-ptr-fwd.hpp b/compat/borrowed-ptr-fwd.hpp
index b28c6a71..e773a089 100644
--- a/compat/borrowed-ptr-fwd.hpp
+++ b/compat/borrowed-ptr-fwd.hpp
@@ -19,6 +19,9 @@ class bptr final // NOLINT(*-special-member-functions)
     T* ptr; // todo add simple_bptr that doesn't allow casting. should only have the control block member variable.
     detail_borrowed_ptr::control_block_* blk;
 
+    explicit constexpr bptr(NoInitT) noexcept;
+    explicit constexpr bptr(DirectInitT, T* ptr, detail_borrowed_ptr::control_block_* blk) noexcept;
+
 public:
     template<typename... Ts>
     requires std::is_constructible_v<T, Ts&&...>
@@ -26,7 +29,6 @@ public:
 
     constexpr bptr(std::nullptr_t) noexcept; // NOLINT(*-explicit-conversions)
     constexpr bptr() noexcept;
-    explicit constexpr bptr(NoInitT) noexcept;
     explicit bptr(T* ptr) noexcept;
     ~bptr() noexcept;
 
@@ -43,9 +45,9 @@ public:
     uint32_t use_count() const noexcept;
     explicit operator bool() const noexcept;
 
-    template<typename U>
-    requires detail_borrowed_ptr::StaticCastable<T, U>
-    bptr<U> static_pointer_cast() noexcept;
+    template<typename U> friend class bptr;
+    template<typename Tʹ, typename U>
+    friend bptr<U> static_pointer_cast(const bptr<Tʹ>& p) noexcept;
 };
 
 } // namespace floormat
diff --git a/compat/borrowed-ptr.cpp b/compat/borrowed-ptr.cpp
index 2eac9ad7..67a55ed7 100644
--- a/compat/borrowed-ptr.cpp
+++ b/compat/borrowed-ptr.cpp
@@ -36,3 +36,11 @@ struct Foo {};
 struct Bar : Foo {};
 struct Baz {};
 } // namespace
+
+namespace floormat {
+
+template struct detail_borrowed_ptr::control_block<Foo>;
+template class bptr<Foo>;
+template bptr<Bar> static_pointer_cast(const bptr<Foo>&) noexcept;
+
+} // namespace floormat
diff --git a/compat/borrowed-ptr.hpp b/compat/borrowed-ptr.hpp
index 5134f279..872902a2 100644
--- a/compat/borrowed-ptr.hpp
+++ b/compat/borrowed-ptr.hpp
@@ -3,16 +3,22 @@
 
 namespace floormat {
 
-template<typename T> constexpr bptr<T>::bptr(NoInitT) noexcept {};
 template<typename T> constexpr bptr<T>::bptr(std::nullptr_t) noexcept: ptr{nullptr}, blk{nullptr} {}
 template<typename T> constexpr bptr<T>::bptr() noexcept: bptr{nullptr} {}
 
-template<typename T> bptr(T* ptr) -> bptr<T>;
-
 template<typename T, typename U>
-CORRADE_ALWAYS_INLINE bptr<U> static_pointer_cast(const bptr<T>& p) noexcept
+bptr<U> static_pointer_cast(const bptr<T>& p) noexcept
 {
-    return p.template static_pointer_cast<U>();
+    static_assert(detail_borrowed_ptr::StaticCastable<T, U>);
+
+    if (auto* blk = p.blk) [[likely]]
+    {
+        auto* ptr = static_cast<U*>(p.ptr);
+        blk->incr();
+        return bptr<U>{DirectInit, ptr, blk};
+    }
+    else
+        return bptr<U>{nullptr};
 }
 
 } // namespace floormat
diff --git a/compat/borrowed-ptr.inl b/compat/borrowed-ptr.inl
index 7cb373ca..2faca999 100644
--- a/compat/borrowed-ptr.inl
+++ b/compat/borrowed-ptr.inl
@@ -69,6 +69,14 @@ bptr{ new T{ forward<Ts...>(args...) } }
 {
 }
 
+template<typename T> constexpr bptr<T>::bptr(NoInitT) noexcept {};
+
+template<typename T>
+constexpr bptr<T>::bptr(DirectInitT, T* ptr, detail_borrowed_ptr::control_block_* blk) noexcept:
+    ptr{ptr}, blk{blk}
+{
+}
+
 template<typename T>
 bptr<T>::bptr(T* ptr) noexcept:
     ptr{ptr},
@@ -139,17 +147,4 @@ bptr<T>& bptr<T>::operator=(bptr<Y>&& other) noexcept
     return *this;
 }
 
-template<typename T>
-template<typename U>
-requires detail_borrowed_ptr::StaticCastable<T, U>
-bptr<U> bptr<T>::static_pointer_cast() noexcept
-{
-    auto ret = bptr<T>{NoInit};
-    ret.blk = blk;
-    if (ret.blk) [[likely]]
-        ret.blk->incr();
-    ret.ptr = static_cast<T*>(ptr);
-    return ret;
-}
-
 } // namespace floormat