From c8b73031d8a9f7770410c9d0e6da5b230e501e85 Mon Sep 17 00:00:00 2001
From: Steven Le Rouzic <steven.lerouzic@gmail.com>
Date: Wed, 12 Mar 2025 00:08:18 +0100
Subject: Remove convertible_from

---
 asl/base/meta.hpp          |  7 ++-----
 asl/base/meta_tests.cpp    | 26 +++++++++++++-------------
 asl/types/box.hpp          |  2 +-
 asl/types/box_tests.cpp    |  8 ++++----
 asl/types/option.hpp       | 12 ++++++------
 asl/types/option_tests.cpp | 16 ++++++++--------
 asl/types/span.hpp         |  2 +-
 asl/types/status_or.hpp    |  6 +++---
 todo.txt                   |  2 +-
 9 files changed, 39 insertions(+), 42 deletions(-)

diff --git a/asl/base/meta.hpp b/asl/base/meta.hpp
index 8376d5c..8bebf2f 100644
--- a/asl/base/meta.hpp
+++ b/asl/base/meta.hpp
@@ -87,14 +87,11 @@ template<typename T> concept trivially_destructible = __is_trivially_destructibl
 template<typename T> concept copyable = copy_constructible<T> && copy_assignable<T>;
 template<typename T> concept moveable = move_constructible<T> && move_assignable<T>;
 
-template<typename To, typename From>
-concept convertible_from = __is_convertible(From, To);
-
 template<typename From, typename To>
 concept convertible_to = __is_convertible(From, To);
 
 template<typename Derived, class Base>
-concept derived_from = __is_class(Derived) && __is_class(Base) && convertible_from<const volatile Base*, const volatile Derived*>;
+concept derived_from = __is_class(Derived) && __is_class(Base) && convertible_to<const volatile Derived*, const volatile Base*>;
 
 using nullptr_t = decltype(nullptr);
 
@@ -258,7 +255,7 @@ concept derefs_as = is_object<To> &&
     (convertible_to<un_ref_t<From>&, To&> || _dereferenceable_as_convertible<un_ref_t<From>, To>);
 
 template<typename To, derefs_as<To> From>
-constexpr auto&& deref(From&& from) // NOLINT(*forward*)
+constexpr auto&& deref(From&& from) // NOLINT(*-missing-std-forward)
 {
     if constexpr (_dereferenceable_as_convertible<From, To>)
     {
diff --git a/asl/base/meta_tests.cpp b/asl/base/meta_tests.cpp
index 6c8efab..490b453 100644
--- a/asl/base/meta_tests.cpp
+++ b/asl/base/meta_tests.cpp
@@ -205,19 +205,19 @@ class C {};
 class D { public: operator C() { return c; } C c; }; // NOLINT
 class E { public: template<class T> E(T&&) {} }; // NOLINT
 
-static_assert(asl::convertible_from<Base*, Derived*>);
-static_assert(!asl::convertible_from<Derived*, Base*>);
-static_assert(asl::convertible_from<C, D>);
-static_assert(!asl::convertible_from<C*, Derived*>);
-static_assert(asl::convertible_from<E, Base>);
-
-static_assert(!asl::convertible_from<int16_t(&)[], int32_t(&)[]>);
-static_assert(asl::convertible_from<const int16_t(&)[], int16_t(&)[]>);
-static_assert(asl::convertible_from<const int16_t(&)[], const int16_t(&)[]>);
-static_assert(asl::convertible_from<int16_t(&)[], int16_t(&)[]>);
-static_assert(!asl::convertible_from<int32_t(&)[], int16_t(&)[]>);
-static_assert(!asl::convertible_from<int16_t(&)[], const int16_t(&)[]>);
-static_assert(!asl::convertible_from<C(&)[], D(&)[]>);
+static_assert(asl::convertible_to<Derived*, Base*>);
+static_assert(!asl::convertible_to<Base*, Derived*>);
+static_assert(asl::convertible_to<D, C>);
+static_assert(!asl::convertible_to<Derived*, C*>);
+static_assert(asl::convertible_to<Base, E>);
+
+static_assert(!asl::convertible_to<int32_t(&)[], int16_t(&)[]>);
+static_assert(asl::convertible_to<int16_t(&)[], const int16_t(&)[]>);
+static_assert(asl::convertible_to<const int16_t(&)[], const int16_t(&)[]>);
+static_assert(asl::convertible_to<int16_t(&)[], int16_t(&)[]>);
+static_assert(!asl::convertible_to<int16_t(&)[], int32_t(&)[]>);
+static_assert(!asl::convertible_to<const int16_t(&)[], int16_t(&)[]>);
+static_assert(!asl::convertible_to<D(&)[], C(&)[]>);
 
 static_assert(asl::derived_from<Derived, Base>);
 static_assert(!asl::derived_from<Base, Derived>);
diff --git a/asl/types/box.hpp b/asl/types/box.hpp
index bb4e620..82704d7 100644
--- a/asl/types/box.hpp
+++ b/asl/types/box.hpp
@@ -40,7 +40,7 @@ public:
     {}
 
     template<is_object U>
-    requires convertible_from<T*, U*>
+    requires convertible_to<U*, T*>
     constexpr box(box<U, Allocator>&& other) // NOLINT(*explicit*,*-not-moved)
         : m_ptr{exchange(other.m_ptr, nullptr)}
         , m_alloc{std::move(other.m_alloc)}
diff --git a/asl/types/box_tests.cpp b/asl/types/box_tests.cpp
index b3c55b2..1ee5f0e 100644
--- a/asl/types/box_tests.cpp
+++ b/asl/types/box_tests.cpp
@@ -94,10 +94,10 @@ public:
     int number() override { return 2; }
 };
 
-static_assert(asl::convertible_from<asl::box<Base>, asl::box<Derived>>);
-static_assert(asl::convertible_from<asl::box<Base>, asl::box<Base>>);
-static_assert(!asl::convertible_from<asl::box<Derived>, asl::box<Base>>);
-static_assert(!asl::convertible_from<asl::box<int>, asl::box<float>>);
+static_assert(asl::convertible_to<asl::box<Derived>, asl::box<Base>>);
+static_assert(asl::convertible_to<asl::box<Base>, asl::box<Base>>);
+static_assert(!asl::convertible_to<asl::box<Base>, asl::box<Derived>>);
+static_assert(!asl::convertible_to<asl::box<float>, asl::box<int>>);
 
 ASL_TEST(derived)
 {
diff --git a/asl/types/option.hpp b/asl/types/option.hpp
index 9c317b0..982c63d 100644
--- a/asl/types/option.hpp
+++ b/asl/types/option.hpp
@@ -110,7 +110,7 @@ public:
     constexpr option(nullopt_t) requires kHasNiche : m_payload{in_place, niche_t{}} {}
 
     template<typename U = T>
-    constexpr explicit (!convertible_from<T, U&&>)
+    constexpr explicit (!convertible_to<U&&, T>)
     option(U&& value)
         requires (
             kHasNiche &&
@@ -121,7 +121,7 @@ public:
     {}
 
     template<typename U = T>
-    constexpr explicit (!convertible_from<T, U&&>)
+    constexpr explicit (!convertible_to<U&&, T>)
     option(U&& value)
         requires (
             !kHasNiche &&
@@ -159,7 +159,7 @@ public:
     }
 
     template<typename U>
-    constexpr explicit (!convertible_from<T, const U&>)
+    constexpr explicit (!convertible_to<const U&, T>)
     option(const option<U>& other)
         requires (
             constructible_from<T, const U&> &&
@@ -174,7 +174,7 @@ public:
     }
 
     template<typename U>
-    constexpr explicit (!convertible_from<T, U&&>)
+    constexpr explicit (!convertible_to<U&&, T>)
     option(option<U>&& other)
         requires (
             constructible_from<T, U&&> &&
@@ -377,14 +377,14 @@ public:
 
     template<typename U>
     constexpr T value_or(U&& other_value) const&
-        requires copy_constructible<T> && convertible_from<T, U&&>
+        requires copy_constructible<T> && convertible_to<U&&, T>
     {
         return has_value() ? value() : static_cast<T>(std::forward<U>(other_value));
     }
 
     template<typename U>
     constexpr T value_or(U&& other_value) &&
-        requires move_constructible<T> && convertible_from<T, U&&>
+        requires move_constructible<T> && convertible_to<U&&, T>
     {
         return has_value() ? std::move(value()) : static_cast<T>(std::forward<U>(other_value));
     }
diff --git a/asl/types/option_tests.cpp b/asl/types/option_tests.cpp
index d08c94a..64ddfa6 100644
--- a/asl/types/option_tests.cpp
+++ b/asl/types/option_tests.cpp
@@ -62,20 +62,20 @@ static_assert(!asl::move_assignable<asl::option<Pinned>>);
 static_assert(asl::assignable_from<asl::option<Base*>&, asl::option<Derived*>>);
 static_assert(!asl::assignable_from<asl::option<Derived*>&, asl::option<Base*>>);
 
-static_assert(asl::convertible_from<asl::option<Base*>, asl::option<Derived*>>);
-static_assert(!asl::convertible_from<asl::option<Derived*>, asl::option<Base*>>);
+static_assert(asl::convertible_to<asl::option<Derived*>, asl::option<Base*>>);
+static_assert(!asl::convertible_to<asl::option<Base*>, asl::option<Derived*>>);
 
 class ExplicitConversion { public: explicit ExplicitConversion(int) {} };
 class ImplicitConversion { public: ImplicitConversion(int) {} }; // NOLINT
 
-static_assert(!asl::convertible_from<ExplicitConversion, int>);
-static_assert(asl::convertible_from<ImplicitConversion, int>);
+static_assert(!asl::convertible_to<int, ExplicitConversion>);
+static_assert(asl::convertible_to<int, ImplicitConversion>);
 
-static_assert(!asl::convertible_from<asl::option<ExplicitConversion>, int>);
-static_assert(asl::convertible_from<asl::option<ImplicitConversion>, int>);
+static_assert(!asl::convertible_to<int, asl::option<ExplicitConversion>>);
+static_assert(asl::convertible_to<int, asl::option<ImplicitConversion>>);
 
-static_assert(!asl::convertible_from<asl::option<ExplicitConversion>, asl::option<int>>);
-static_assert(asl::convertible_from<asl::option<ImplicitConversion>, asl::option<int>>);
+static_assert(!asl::convertible_to<asl::option<int>, asl::option<ExplicitConversion>>);
+static_assert(asl::convertible_to<asl::option<int>, asl::option<ImplicitConversion>>);
 
 static_assert(asl::trivially_copy_constructible<asl::option<int>>);
 static_assert(asl::trivially_copy_constructible<asl::option<TrivialType>>);
diff --git a/asl/types/span.hpp b/asl/types/span.hpp
index bb2257a..8585f17 100644
--- a/asl/types/span.hpp
+++ b/asl/types/span.hpp
@@ -95,7 +95,7 @@ public:
                 kIsDynamic ||
                 is_dynamic(kOtherSize) ||
                 kOtherSize == kSize
-            ) && convertible_from<T(&)[], U(&)[]>
+            ) && convertible_to<U(&)[], T(&)[]>
         )
         : span{static_cast<U*>(other.data()), other.size()}
     {
diff --git a/asl/types/status_or.hpp b/asl/types/status_or.hpp
index be6bb06..7794596 100644
--- a/asl/types/status_or.hpp
+++ b/asl/types/status_or.hpp
@@ -114,7 +114,7 @@ public:
     status_or& operator=(status status) = delete;
 
     template<typename U = T>
-    constexpr explicit (!convertible_from<T, U&&>)
+    constexpr explicit (!convertible_to<U&&, T>)
     status_or(U&& value)
         requires (
             constructible_from<T, U&&> &&
@@ -141,14 +141,14 @@ public:
 
     template<typename U>
     constexpr T value_or(U&& other_value) const&
-        requires copy_constructible<T> && convertible_from<T, U&&>
+        requires copy_constructible<T> && convertible_to<U&&, T>
     {
         return ok() ? value() : static_cast<T>(std::forward<U>(other_value));
     }
 
     template<typename U>
     constexpr T value_or(U&& other_value) &&
-        requires move_constructible<T> && convertible_from<T, U&&>
+        requires move_constructible<T> && convertible_to<U&&, T>
     {
         return ok() ? std::move(value()) : static_cast<T>(std::forward<U>(other_value));
     }
diff --git a/todo.txt b/todo.txt
index 9a88465..8b13789 100644
--- a/todo.txt
+++ b/todo.txt
@@ -1 +1 @@
-remove convertible_from
+
-- 
cgit