From 8034ce643d36e8cbe4c4d6bc9e154aaf2eb08597 Mon Sep 17 00:00:00 2001
From: Steven Le Rouzic <steven.lerouzic@gmail.com>
Date: Wed, 26 Feb 2025 00:14:00 +0100
Subject: Use deducing-this in some places

---
 asl/types/maybe_uninit.hpp       |  8 +++--
 asl/types/maybe_uninit_tests.cpp |  5 +++
 asl/types/option.hpp             | 77 +++++++++++-----------------------------
 asl/types/status_or.hpp          | 20 +++--------
 4 files changed, 35 insertions(+), 75 deletions(-)

(limited to 'asl')

diff --git a/asl/types/maybe_uninit.hpp b/asl/types/maybe_uninit.hpp
index 9134fe9..36429e4 100644
--- a/asl/types/maybe_uninit.hpp
+++ b/asl/types/maybe_uninit.hpp
@@ -64,9 +64,11 @@ public:
     }
 
     // @Safety Value must have been initialized
-    constexpr const T& as_init_unsafe() const& { return m_value; }
-    constexpr T&       as_init_unsafe() &      { return m_value; }
-    constexpr T&&      as_init_unsafe() &&     { return ASL_MOVE(m_value); }
+    template<typename Self>
+    constexpr auto&& as_init_unsafe(this Self&& self)
+    {
+        return ASL_FWD_LIKE(decltype(self), ASL_FWD(self).m_value);
+    }
 };
 
 } // namespace asl
diff --git a/asl/types/maybe_uninit_tests.cpp b/asl/types/maybe_uninit_tests.cpp
index 4b414cd..16786a7 100644
--- a/asl/types/maybe_uninit_tests.cpp
+++ b/asl/types/maybe_uninit_tests.cpp
@@ -20,3 +20,8 @@ TEST_TYPE_PROPERTIES(trivially_copy_assignable);
 TEST_TYPE_PROPERTIES(trivially_move_assignable);
 TEST_TYPE_PROPERTIES(trivially_destructible);
 
+static_assert(asl::same_as<int&, decltype(asl::declval<asl::maybe_uninit<int>&>().as_init_unsafe())>);
+static_assert(asl::same_as<int&&, decltype(asl::declval<asl::maybe_uninit<int>&&>().as_init_unsafe())>);
+static_assert(asl::same_as<const int&, decltype(asl::declval<const asl::maybe_uninit<int>&>().as_init_unsafe())>);
+static_assert(asl::same_as<const int&&, decltype(asl::declval<const asl::maybe_uninit<int>>().as_init_unsafe())>);
+static_assert(asl::same_as<int&&, decltype(asl::declval<asl::maybe_uninit<int>>().as_init_unsafe())>);
diff --git a/asl/types/option.hpp b/asl/types/option.hpp
index 5cbb759..e79c09c 100644
--- a/asl/types/option.hpp
+++ b/asl/types/option.hpp
@@ -395,70 +395,35 @@ public:
         return value();
     }
 
-    template<typename F>
-    constexpr auto and_then(F&& f) &
-        requires is_option<result_of_t<F(T&)>>
-    {
-        if (has_value())
-        {
-            return invoke(ASL_FWD(f), value());
-        }
-        return un_cvref_t<result_of_t<F(T&)>>{};
-    }
-
-    template<typename F>
-    constexpr auto and_then(F&& f) const&
-        requires is_option<result_of_t<F(const T&)>>
-    {
-        if (has_value())
-        {
-            return invoke(ASL_FWD(f), value());
-        }
-        return un_cvref_t<result_of_t<F(const T&)>>{};
-    }
-
-    template<typename F>
-    constexpr auto and_then(F&& f) &&
-        requires is_option<result_of_t<F(T)>>
-    {
-        if (has_value())
-        {
-            return invoke(ASL_FWD(f), ASL_MOVE(value()));
-        }
-        return un_cvref_t<result_of_t<F(T)>>{};
-    }
-
-    template<typename F>
-    constexpr auto transform(F&& f) &
-    {
-        using U = un_cvref_t<result_of_t<F(T&)>>;
-        if (has_value())
-        {
-            return option<U>{ invoke(ASL_FWD(f), value()) };
-        }
-        return option<U>{};
-    }
-
-    template<typename F>
-    constexpr auto transform(F&& f) const&
+    template<
+        typename F,
+        typename Self,
+        typename Result = result_of_t<F(copy_cref_t<Self&&, T>)>
+    >
+    constexpr auto and_then(this Self&& self, F&& f)
+        requires is_option<Result>
     {
-        using U = un_cvref_t<result_of_t<F(const T&)>>;
-        if (has_value())
+        if (self.has_value())
         {
-            return option<U>{ invoke(ASL_FWD(f), value()) };
+            return invoke(ASL_FWD(f), ASL_FWD_LIKE(decltype(self), ASL_FWD(self).value()));
         }
-        return option<U>{};
+        return Result{ asl::nullopt };
     }
 
-    template<typename F>
-    constexpr auto transform(F&& f) &&
+    template<
+        typename F,
+        typename Self,
+        typename Result = result_of_t<F(copy_cref_t<Self&&, T>)>
+    >
+    constexpr auto transform(this Self&& self, F&& f)
     {
-        using U = un_cvref_t<result_of_t<F(T)>>;
-        if (has_value())
+        if (self.has_value())
         {
-            return option<U>{ invoke(ASL_FWD(f), ASL_MOVE(value())) };
+            return option<un_cvref_t<Result>>{
+                invoke(ASL_FWD(f), ASL_FWD_LIKE(decltype(self), ASL_FWD(self).value()))
+            };
         }
-        return option<U>{};
+        return option<un_cvref_t<Result>>{ asl::nullopt };
     }
 
     template<typename F>
diff --git a/asl/types/status_or.hpp b/asl/types/status_or.hpp
index 07cfd7f..5771d58 100644
--- a/asl/types/status_or.hpp
+++ b/asl/types/status_or.hpp
@@ -129,23 +129,11 @@ public:
 
     constexpr status&& throw_status() && { return ASL_MOVE(m_status); }
 
-    // @Todo(C++23) Deducing this
-    constexpr const T& value() const&
+    template<typename Self>
+    constexpr auto&& value(this Self&& self)
     {
-        ASL_ASSERT_RELEASE(ok());
-        return m_value.as_init_unsafe();
-    }
-
-    constexpr T& value() &
-    {
-        ASL_ASSERT_RELEASE(ok());
-        return m_value.as_init_unsafe();
-    }
-
-    constexpr T&& value() &&
-    {
-        ASL_ASSERT_RELEASE(ok());
-        return ASL_MOVE(m_value.as_init_unsafe());
+        ASL_ASSERT_RELEASE(self.ok());
+        return ASL_FWD(self).m_value.as_init_unsafe();
     }
 
     template<typename U>
-- 
cgit