From 237c0b4d197e4eb7ac09246e2ff1ef1578ba5761 Mon Sep 17 00:00:00 2001
From: kayomn <kayomn@kayomn.net>
Date: Thu, 23 Feb 2023 14:59:29 +0000
Subject: [PATCH] Replace coral::callable with coral::closure

---
 source/app.cpp         |  6 +++---
 source/coral.cpp       | 37 ++++++++++++++++++-------------------
 source/coral/files.cpp |  4 ++--
 source/oar.cpp         |  4 ++--
 4 files changed, 25 insertions(+), 26 deletions(-)

diff --git a/source/app.cpp b/source/app.cpp
index a97f08a..de3f7d2 100644
--- a/source/app.cpp
+++ b/source/app.cpp
@@ -154,7 +154,7 @@ struct sandboxed_fs : public coral::fs {
 		return this->access_rules;
 	}
 
-	void read_file(coral::path const & file_path, coral::callable<void(coral::file_reader &)> const & then) override {
+	void read_file(coral::path const & file_path, coral::closure<void(coral::file_reader &)> const & then) override {
 		if (!this->access_rules.can_read) return;
 
 		native_path sandbox_file_path;
@@ -183,7 +183,7 @@ struct sandboxed_fs : public coral::fs {
 			return;
 	}
 
-	void write_file(coral::path const & file_path, coral::callable<void(coral::file_writer &)> const & then) override {
+	void write_file(coral::path const & file_path, coral::closure<void(coral::file_writer &)> const & then) override {
 		if (!this->access_rules.can_write) return;
 
 		native_path sandbox_file_path;
@@ -260,7 +260,7 @@ export namespace app {
 			return this->resources_archive;
 		}
 
-		static int run(coral::path const & title, coral::callable<int(client &)> const & start) {
+		static int run(coral::path const & title, coral::closure<int(client &)> const & start) {
 			constexpr int windowpos {SDL_WINDOWPOS_UNDEFINED};
 			constexpr coral::u32 windowflags {SDL_WINDOW_HIDDEN};
 			constexpr int window_width {640};
diff --git a/source/coral.cpp b/source/coral.cpp
index 1fcf1ea..7839d95 100644
--- a/source/coral.cpp
+++ b/source/coral.cpp
@@ -420,45 +420,44 @@ export namespace coral {
 		u8 buffer[buffer_size + 1];
 	};
 
-	template<typename> struct callable;
+	template<typename> struct closure;
 
 	/**
-	 * Type-erasing wrapper for functor types that have a call operator with a return value
-	 * matching `return_value` and arguments matching `argument_values`.
+	 * Type-erasing view wrapper for both function and functor types that have a call operator with
+	 * a return value matching `return_value` and arguments matching `argument_values`.
+	 *
+	 * **Note**: closures take no ownership of allocated memory, making it the responsibility of
+	 * the caller to manage the lifetime of any functor assigned to it.
 	 */
-	template<typename returns, typename... arguments> struct callable<returns(arguments...)> {
+	template<typename returns, typename... arguments> struct closure<returns(arguments...)> {
 		using function = returns(*)(arguments...);
 
-		callable(function callable_function) {
-			this->dispatcher = [](u8 const * context, arguments... dispatch_arguments) -> returns {
-				return (*reinterpret_cast<function const *>(context))(dispatch_arguments...);
+		closure(function callable_function) {
+			this->dispatch = [](void const * context, arguments... dispatch_arguments) -> returns {
+				return (reinterpret_cast<function const *>(context))(dispatch_arguments...);
 			};
 
-			new (this->capture) function{callable_function};
+			this->context = callable_function;
 		}
 
-		callable(callable const &) = delete;
+		closure(closure const &) = delete;
 
-		template<typename functor> callable(functor const & callable_functor) {
-			static_assert(sizeof(functor) < capture_size);
-
-			this->dispatcher = [](u8 const * context, arguments... dispatch_arguments) -> returns {
+		template<typename functor> closure(functor && callable_functor) {
+			this->dispatch = [](void const * context, arguments... dispatch_arguments) -> returns {
 				return (*reinterpret_cast<functor const*>(context))(dispatch_arguments...);
 			};
 
-			new (this->capture) functor{callable_functor};
+			this->context = &callable_functor;
 		}
 
 		returns operator()(arguments const &... call_arguments) const {
-			return this->dispatcher(this->capture, call_arguments...);
+			return this->dispatch(this->context, call_arguments...);
 		}
 
 		private:
-		static constexpr usize capture_size = 24;
+		void const * context;
 
-		returns(* dispatcher)(u8 const *, arguments...);
-
-		u8 capture[capture_size];
+		returns(* dispatch)(void const *, arguments...);
 	};
 
 	/**
diff --git a/source/coral/files.cpp b/source/coral/files.cpp
index ae07d07..100a35c 100644
--- a/source/coral/files.cpp
+++ b/source/coral/files.cpp
@@ -144,7 +144,7 @@ export namespace coral {
 		 *
 		 * Once `then` returns, access to the file is closed automatically.
 		 */
-		virtual void read_file(path const & file_path, callable<void(file_reader &)> const & then) = 0;
+		virtual void read_file(path const & file_path, closure<void(file_reader &)> const & then) = 0;
 
 		/**
 		 * Attempts to write the file in the file system located at `file_path` relative, calling
@@ -152,6 +152,6 @@ export namespace coral {
 		 *
 		 * Once `then` returns, access to the file is closed automatically.
 		 */
-		virtual void write_file(path const & file_path, callable<void(file_writer &)> const & then) = 0;
+		virtual void write_file(path const & file_path, closure<void(file_writer &)> const & then) = 0;
 	};
 }
diff --git a/source/oar.cpp b/source/oar.cpp
index 9dc338d..4f8c5f8 100644
--- a/source/oar.cpp
+++ b/source/oar.cpp
@@ -179,7 +179,7 @@ export namespace oar {
 		}
 
 		void read_file(coral::path const & file_path,
-			coral::callable<void(coral::file_reader &)> const & then) override {
+			coral::closure<void(coral::file_reader &)> const & then) override {
 
 			if ((this->backing_fs == nullptr) || (this->archive_path.byte_size() == 0)) return;
 
@@ -195,7 +195,7 @@ export namespace oar {
 		}
 
 		void write_file(coral::path const & file_path,
-			coral::callable<void(coral::file_writer &)> const & then) override {
+			coral::closure<void(coral::file_writer &)> const & then) override {
 
 			// Read-only file system.
 		}