From 69188a5a68b649d35976a3a2bc7de030aa59fbc9 Mon Sep 17 00:00:00 2001
From: ruben <rubenperez038@gmail.com>
Date: Sat, 28 Mar 2020 14:37:07 +0000
Subject: [PATCH] Fixed exception specifications for value_holder

---
 include/boost/mysql/async_handler_arg.hpp            | 2 ++
 include/boost/mysql/detail/protocol/value_holder.hpp | 8 ++++++--
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/include/boost/mysql/async_handler_arg.hpp b/include/boost/mysql/async_handler_arg.hpp
index 22c98ad1..f00be70b 100644
--- a/include/boost/mysql/async_handler_arg.hpp
+++ b/include/boost/mysql/async_handler_arg.hpp
@@ -12,6 +12,8 @@ class async_handler_arg
 	error_info err_;
 	T value_;
 public:
+	using value_type = T;
+
 	constexpr async_handler_arg() noexcept = default;
 
 	constexpr async_handler_arg(error_info&& info):
diff --git a/include/boost/mysql/detail/protocol/value_holder.hpp b/include/boost/mysql/detail/protocol/value_holder.hpp
index b7fc51af..244ea66d 100644
--- a/include/boost/mysql/detail/protocol/value_holder.hpp
+++ b/include/boost/mysql/detail/protocol/value_holder.hpp
@@ -2,6 +2,7 @@
 #define INCLUDE_BOOST_MYSQL_DETAIL_PROTOCOL_VALUE_HOLDER_HPP_
 
 #include <utility>
+#include <type_traits>
 
 namespace boost {
 namespace mysql {
@@ -11,13 +12,16 @@ template <typename T>
 struct value_holder
 {
 	using value_type = T;
+	static_assert(std::is_nothrow_default_constructible_v<T>);
 
 	value_type value;
 
-	value_holder(): value{} {};
+	value_holder() noexcept: value{} {};
 
 	template <typename U>
-	explicit constexpr value_holder(U&& u): value(std::forward<U>(u)) {}
+	explicit constexpr value_holder(U&& u)
+		noexcept(std::is_nothrow_constructible_v<T, decltype(u)>):
+		value(std::forward<U>(u)) {}
 
 	constexpr bool operator==(const value_holder<T>& rhs) const { return value == rhs.value; }
 	constexpr bool operator!=(const value_holder<T>& rhs) const { return value != rhs.value; }