From bbe2474e248dceffe89fe7f23ad7abce5452fc97 Mon Sep 17 00:00:00 2001
From: Stanislaw Halik <sthalik@misaki.pl>
Date: Sat, 4 May 2024 13:49:20 +0200
Subject: w a

---
 compat/borrowed-ptr-fwd.hpp | 51 +++++++++++++++++++++++++++++++++++++++++++++
 compat/borrowed-ptr.cpp     | 13 +++++-------
 compat/borrowed-ptr.hpp     | 48 +++++++-----------------------------------
 compat/borrowed-ptr.inl     | 11 ++++++----
 4 files changed, 70 insertions(+), 53 deletions(-)
 create mode 100644 compat/borrowed-ptr-fwd.hpp

diff --git a/compat/borrowed-ptr-fwd.hpp b/compat/borrowed-ptr-fwd.hpp
new file mode 100644
index 00000000..b28c6a71
--- /dev/null
+++ b/compat/borrowed-ptr-fwd.hpp
@@ -0,0 +1,51 @@
+#pragma once
+
+namespace floormat::detail_borrowed_ptr {
+
+struct control_block_;
+
+template<typename From, typename To>
+concept StaticCastable = requires(From* ptr) {
+    static_cast<To*>(ptr);
+};
+
+} // namespace floormat::detail_borrowed_ptr
+
+namespace floormat {
+
+template<typename T>
+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;
+
+public:
+    template<typename... Ts>
+    requires std::is_constructible_v<T, Ts&&...>
+    explicit bptr(InPlaceInitT, Ts&&... args) noexcept;
+
+    constexpr bptr(std::nullptr_t) noexcept; // NOLINT(*-explicit-conversions)
+    constexpr bptr() noexcept;
+    explicit constexpr bptr(NoInitT) noexcept;
+    explicit bptr(T* ptr) noexcept;
+    ~bptr() noexcept;
+
+    template<typename Y> requires std::is_convertible_v<Y*, T*> bptr(const bptr<Y>&) noexcept;
+    template<typename Y> requires std::is_convertible_v<Y*, T*> bptr(bptr<Y>&&) noexcept;
+    template<typename Y> requires std::is_convertible_v<Y*, T*> bptr& operator=(const bptr<Y>&) noexcept;
+    template<typename Y> requires std::is_convertible_v<Y*, T*> bptr& operator=(bptr<Y>&&) noexcept;
+
+    void swap() noexcept;
+    T* get() noexcept;
+    const T* get() const noexcept;
+    T& operator*() const noexcept;
+    T* operator->() const noexcept;
+    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;
+};
+
+} // namespace floormat
diff --git a/compat/borrowed-ptr.cpp b/compat/borrowed-ptr.cpp
index 8c05b751..2eac9ad7 100644
--- a/compat/borrowed-ptr.cpp
+++ b/compat/borrowed-ptr.cpp
@@ -31,11 +31,8 @@ uint32_t control_block_::count() const noexcept { return _count; }
 
 } // namespace floormat::detail_borrowed_ptr
 
-namespace floormat {
-
-namespace { struct Foo {}; }
-
-template struct detail_borrowed_ptr::control_block<Foo>;
-template class bptr<Foo>;
-
-} // namespace floormat
+namespace {
+struct Foo {};
+struct Bar : Foo {};
+struct Baz {};
+} // namespace
diff --git a/compat/borrowed-ptr.hpp b/compat/borrowed-ptr.hpp
index 10b95be9..5134f279 100644
--- a/compat/borrowed-ptr.hpp
+++ b/compat/borrowed-ptr.hpp
@@ -1,52 +1,18 @@
 #pragma once
-
-namespace floormat::detail_borrowed_ptr {
-struct control_block_;
-} // namespace floormat::detail_borrowed_ptr
+#include "borrowed-ptr-fwd.hpp"
 
 namespace floormat {
-template<typename T> class bptr;
-template<typename T> bptr<T> static_pointer_cast(const bptr<T>& p);
-
-template<typename T>
-class bptr final // NOLINT(*-special-member-functions)
-{
-    T* ptr; // todo add simple_bptr that doesn't allow casting. should only have the control block element.
-    detail_borrowed_ptr::control_block_* blk;
-
-    constexpr bptr(NoInitT) noexcept;
-
-public:
-    template<typename... Ts>
-    requires std::is_constructible_v<T, Ts&&...>
-    explicit bptr(InPlaceInitT, Ts&&... args) noexcept;
-
-    constexpr bptr(std::nullptr_t) noexcept; // NOLINT(*-explicit-conversions)
-    constexpr bptr() noexcept;
-    explicit bptr(T* ptr) noexcept;
-    ~bptr() noexcept;
-
-    template<typename Y> requires std::is_convertible_v<Y*, T*> bptr(const bptr<Y>&) noexcept;
-    template<typename Y> requires std::is_convertible_v<Y*, T*> bptr(bptr<Y>&&) noexcept;
-    template<typename Y> requires std::is_convertible_v<Y*, T*> bptr& operator=(const bptr<Y>&) noexcept;
-    template<typename Y> requires std::is_convertible_v<Y*, T*> bptr& operator=(bptr<Y>&&) noexcept;
-
-    void swap() noexcept;
-    T* get() noexcept;
-    const T* get() const noexcept;
-    T& operator*() const noexcept;
-    T* operator->() const noexcept;
-    uint32_t use_count() const noexcept;
-    explicit operator bool() const noexcept;
-
-    friend bptr<T> static_pointer_cast<T>(const bptr<T>& p);
-};
 
 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
+{
+    return p.template static_pointer_cast<U>();
+}
+
 } // namespace floormat
diff --git a/compat/borrowed-ptr.inl b/compat/borrowed-ptr.inl
index 7302c857..7cb373ca 100644
--- a/compat/borrowed-ptr.inl
+++ b/compat/borrowed-ptr.inl
@@ -82,6 +82,7 @@ bptr<T>::~bptr() noexcept
     if (blk)
         blk->decr();
     //blk = reinterpret_cast<T*>(-1);
+    //blk = nullptr;
 }
 
 template<typename T>
@@ -138,14 +139,16 @@ bptr<T>& bptr<T>::operator=(bptr<Y>&& other) noexcept
     return *this;
 }
 
-template<typename T, typename U>
-bptr<T> static_pointer_cast(const bptr<U>& p)
+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 = p.blk;
+    ret.blk = blk;
     if (ret.blk) [[likely]]
         ret.blk->incr();
-    ret.ptr = static_cast<T*>(p.ptr);
+    ret.ptr = static_cast<T*>(ptr);
     return ret;
 }
 
-- 
cgit v1.2.3