From e8db08931ae215b7da757302dad87b561a065c8a Mon Sep 17 00:00:00 2001
From: King_DuckZ <king_duckz@gmx.com>
Date: Tue, 24 May 2022 16:07:16 +0200
Subject: [PATCH] Add equality operators

---
 include/wrenpp/detail/module_and_name.hpp | 43 +++++++++++++++++++++++
 meson.build                               |  1 +
 src/module_and_name.cpp                   | 30 ++++++++++++++++
 3 files changed, 74 insertions(+)
 create mode 100644 src/module_and_name.cpp

diff --git a/include/wrenpp/detail/module_and_name.hpp b/include/wrenpp/detail/module_and_name.hpp
index a497c31..7dd3bbd 100644
--- a/include/wrenpp/detail/module_and_name.hpp
+++ b/include/wrenpp/detail/module_and_name.hpp
@@ -20,13 +20,20 @@
 #include "string_bt.hpp"
 #include <string_view>
 #include <cstdint>
+#include <cassert>
+#include <type_traits>
 
 namespace wren {
+	class ModuleAndName;
+
 	namespace detail {
 		template <dhandy::bt::string S>
 		struct ModuleAndNameStaticStorage {
 			static constexpr const auto value = S;
 		};
+
+		[[gnu::const]]
+		bool deep_equal (const ModuleAndName& a, const ModuleAndName& b) noexcept;
 	} //unnamed namespace
 
 	//Non-owning, lightweight class for storing a module nome/class name pair.
@@ -40,10 +47,15 @@ namespace wren {
 	//of this class get hardcoded in the dynamic functions that DynafuncMaker
 	//spits out.
 	class ModuleAndName {
+		friend bool detail::deep_equal(const ModuleAndName&, const ModuleAndName&) noexcept;
 	public:
 		constexpr ModuleAndName();
 		constexpr ModuleAndName (const char* base, std::uint32_t hash, std::size_t mod_name_len, std::size_t class_name_len);
 
+		constexpr bool operator==(const ModuleAndName& other) const noexcept;
+		constexpr bool operator!=(const ModuleAndName& other) const noexcept;
+		constexpr bool deep_equal(const ModuleAndName& other) const noexcept;
+
 		constexpr const char* module_name_char() const noexcept { return m_base; }
 		constexpr const char* class_name_char() const noexcept { return m_base + 1 + m_mod_name_len; }
 		constexpr std::size_t module_name_len() const noexcept { return m_mod_name_len; }
@@ -53,6 +65,8 @@ namespace wren {
 		constexpr const char* buffer_address() const noexcept { return m_base; }
 
 	private:
+		constexpr std::size_t raw_buffer_size() const noexcept;
+
 		const char* m_base;
 		std::uint32_t m_hash;
 		std::uint16_t m_mod_name_len;
@@ -85,6 +99,35 @@ namespace wren {
 		m_class_name_len(class_name_len)
 	{}
 
+	constexpr bool ModuleAndName::operator==(const ModuleAndName& other) const noexcept {
+		const bool retval = (this->m_hash == other.m_hash);
+		assert(not retval or deep_equal(other));
+		return retval;
+	}
+
+	constexpr bool ModuleAndName::operator!=(const ModuleAndName& other) const noexcept {
+		return not this->operator==(other);
+	}
+
+	constexpr bool ModuleAndName::deep_equal(const ModuleAndName& other) const noexcept {
+		if (not std::is_constant_evaluated()) {
+			return detail::deep_equal(*this, other);
+		}
+		else {
+			if (this->raw_buffer_size() != other.raw_buffer_size())
+				return false;
+			for (std::size_t z = 0; z < raw_buffer_size(); ++z) {
+				if (this->m_base[z] != other.m_base[z])
+					return false;
+			}
+			return true;
+		}
+	}
+
+	constexpr std::size_t ModuleAndName::raw_buffer_size() const noexcept {
+		return m_mod_name_len + m_class_name_len + 2;
+	}
+
 	template <dhandy::bt::string S1, dhandy::bt::string S2>
 	constexpr ModuleAndName make_module_and_name() {
 		using dhandy::bt::string;
diff --git a/meson.build b/meson.build
index 8bda0ca..e59c60c 100644
--- a/meson.build
+++ b/meson.build
@@ -74,6 +74,7 @@ wrenpp = library(meson.project_name(),
   'src/class_manager.cpp',
   'src/wren_class_name_from_type.cpp',
   'src/crc32.cpp',
+  'src/module_and_name.cpp',
   dependencies: [wren_dep],
   include_directories: public_incl,
   install: (not meson.is_subproject() or get_option('default_library')=='shared'),
diff --git a/src/module_and_name.cpp b/src/module_and_name.cpp
new file mode 100644
index 0000000..a50322e
--- /dev/null
+++ b/src/module_and_name.cpp
@@ -0,0 +1,30 @@
+/* Copyright 2020-2022, Michele Santullo
+ * This file is part of wrenpp.
+ *
+ * Wrenpp is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Wrenpp is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with wrenpp.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "wrenpp/detail/module_and_name.hpp"
+#include <algorithm>
+
+namespace wren::detail {
+	bool deep_equal(const ModuleAndName& a, const ModuleAndName& b) noexcept {
+		const auto a_size = a.raw_buffer_size();
+		const auto b_size = b.raw_buffer_size();
+		if (a_size != b_size)
+			return false;
+
+		return std::equal(a.m_base, a.m_base + a_size, b.m_base);
+	}
+} //namespace wren::detail