Add Handle class.

meson.build

@@ -44,6 +44,7 @@ executable(meson.project_name(),
   'src/wren/def_configuration.cpp',
   'src/wren/dynafunc_maker.cpp',
   'src/dynafunc_' + arch + '_' + os + '.S',
+  'src/wren/handle.cpp',
   dependencies: [wren_dep],
   install: true,
 )

src/wren/handle.cpp

@@ -0,0 +1,14 @@
+#include "handle.hpp"
+#include "vm.hpp"
+#include <cassert>
+
+namespace wren {
+	Handle::~Handle() noexcept {
+		release();
+	}
+
+	void Handle::release() noexcept {
+		assert(m_vm);
+		m_vm->release(*this);
+	}
+} //namespace wren

src/wren/handle.hpp

@@ -0,0 +1,26 @@
+#pragma once
+
+typedef struct WrenHandle WrenHandle;
+
+namespace wren {
+	class VM;
+
+	class Handle {
+	public:
+		explicit Handle (VM* vm, WrenHandle* handle) noexcept :
+			m_handle(handle),
+			m_vm(vm)
+		{
+		}
+
+		~Handle() noexcept;
+		void release() noexcept;
+
+		operator WrenHandle*() { return m_handle; }
+		operator bool() const { return nullptr != m_handle; }
+
+	private:
+		WrenHandle* m_handle;
+		VM* m_vm;
+	};
+} //namespace wren

src/wren/vm.cpp

@@ -164,6 +164,11 @@ namespace wren {
 		return interpret(module_name.c_str(), script.c_str());
 	}
 
+	void VM::release (Handle& handle) noexcept {
+		if (handle)
+			wrenReleaseHandle(m_local->wvm, handle);
+	}
+
 	template <typename T>
 	T VM::slot (int slot_num) {
 		return slot_specialized<T>(m_local->wvm, slot_num);

src/wren/vm.hpp

@@ -2,6 +2,7 @@
 
 #include "has_method.hpp"
 #include "error_type.hpp"
+#include "handle.hpp"
 #include <string>
 #include <memory>
 #include <tuple>
@@ -14,6 +15,7 @@ namespace wren {
 	class Configuration;
 	class VM;
 	class DynafuncMaker;
+	class Handle;
 
 	typedef void(*foreign_method_t)(VM*);
 	typedef void(*finalizer_t)(void*);
@@ -54,6 +56,7 @@ namespace wren {
 
 		void interpret (const char* module_name, const char* script);
 		void interpret (const std::string& module_name, const std::string& script);
+		void release (Handle& handle) noexcept;
 
 		template <typename T> T slot (int slot_num);
 #if __cpp_concepts >= 201907