From 3aa6741b8c8682ff43cb28cbed476723f331a408 Mon Sep 17 00:00:00 2001
From: Nekotekina <nekotekina@gmail.com>
Date: Fri, 24 Aug 2018 14:01:53 +0300
Subject: [PATCH] Simplify error_code

---
 Utilities/types.h | 21 +++++++++------------
 1 file changed, 9 insertions(+), 12 deletions(-)

diff --git a/Utilities/types.h b/Utilities/types.h
index 34913bb0d8..854ae27b39 100644
--- a/Utilities/types.h
+++ b/Utilities/types.h
@@ -905,26 +905,23 @@ struct error_code
 	};
 
 	template<typename ET>
-	struct is_error<ET, std::void_t<decltype(ET::__not_an_error)>> : std::false_type
+	struct is_error<ET, std::enable_if_t<sizeof(ET::__not_an_error) != 0>> : std::false_type
 	{
 	};
 
-	// Not an error constructor
-	template<typename ET, typename = decltype(ET::__not_an_error)>
-	error_code(const ET& value, std::nullptr_t = nullptr)
+	// Common constructor
+	template<typename ET>
+	error_code(const ET& value)
 		: value(static_cast<s32>(value))
 	{
-	}
-
-	// Error constructor
-	template<typename ET, typename = std::enable_if_t<is_error<ET>::value>>
-	error_code(const ET& value)
-		: value(error_report(fmt::get_type_info<fmt_unveil_t<ET>>(), fmt_unveil<ET>::get(value), nullptr, 0))
-	{
+		if constexpr(is_error<ET>::value)
+		{
+			this->value = error_report(fmt::get_type_info<fmt_unveil_t<ET>>(), fmt_unveil<ET>::get(value), nullptr, 0);
+		}
 	}
 
 	// Error constructor (2 args)
-	template<typename ET, typename T2, typename = std::enable_if_t<is_error<ET>::value>>
+	template<typename ET, typename T2>
 	error_code(const ET& value, const T2& value2)
 		: value(error_report(fmt::get_type_info<fmt_unveil_t<ET>>(), fmt_unveil<ET>::get(value), fmt::get_type_info<fmt_unveil_t<T2>>(), fmt_unveil<T2>::get(value2)))
 	{