From 250661b780e4aab528b428c8c7d80d45c44ff600 Mon Sep 17 00:00:00 2001
From: Georg Sauthoff <mail@georg.so>
Date: Fri, 27 May 2016 09:15:28 +0200
Subject: [PATCH] Use Boost Optional if SOL_USE_BOOST is defined

Usecase: Project already uses Boost as dependency, your compiler doesn't
come with <optional> yet and you want to minimize further dependencies.
---
 sol/optional.hpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/sol/optional.hpp b/sol/optional.hpp
index ff28ce91..8fd6cc3a 100644
--- a/sol/optional.hpp
+++ b/sol/optional.hpp
@@ -24,6 +24,8 @@
 
 #if __cplusplus > 201402L
 #include <optional>
+#elif defined(SOL_USE_BOOST)
+#include <boost/optional.hpp>
 #else
 #include "../Optional/optional.hpp"
 #endif // C++ 14
@@ -35,6 +37,11 @@ template <typename T>
 using optional = sol::optional<T>;
 using nullopt_t = std::nullopt_t;
 constexpr nullopt_t nullopt = std::nullopt;
+#elif defined(SOL_USE_BOOST)
+template <typename T>
+using optional = boost::optional<T>;
+using nullopt_t = boost::none_t;
+const nullopt_t nullopt = boost::none;
 #else
 #endif // C++ 14
 }