From c66895ead61a4b2ed9bd60c5d0b136686d10a617 Mon Sep 17 00:00:00 2001
From: Jinhao <cnjinhao@hotmail.com>
Date: Wed, 20 Dec 2017 11:53:29 +0800
Subject: [PATCH] apply C++17 folding expression

---
 include/nana/gui/msgbox.hpp | 6 ++++++
 source/gui/msgbox.cpp       | 2 ++
 2 files changed, 8 insertions(+)

diff --git a/include/nana/gui/msgbox.hpp b/include/nana/gui/msgbox.hpp
index 67840f1a..382bb4d8 100644
--- a/include/nana/gui/msgbox.hpp
+++ b/include/nana/gui/msgbox.hpp
@@ -240,7 +240,11 @@ namespace nana
 		bool show(Args&& ... args)
 		{
 			std::vector<abstract_content*> contents;
+#ifdef _nana_cxx_folding_expression
+			(contents.emplace_back(&args), ...);
+#else
 			_m_fetch_args(contents, std::forward<Args>(args)...);
+#endif
 			if (contents.empty())
 				return false;
 
@@ -270,6 +274,7 @@ namespace nana
 		void min_width_entry_field( unsigned pixels );
 
 	private:
+#ifndef _nana_cxx_folding_expression
 		void _m_fetch_args(std::vector<abstract_content*>&);
 
 		template<typename ...Args>
@@ -278,6 +283,7 @@ namespace nana
 			contents.push_back(&content);
 			_m_fetch_args(contents, std::forward<Args>(args)...);
 		}
+#endif
 
 		bool _m_open(std::vector<abstract_content*>&, bool modal);
 	private:
diff --git a/source/gui/msgbox.cpp b/source/gui/msgbox.cpp
index 75ce6a23..36a7c202 100644
--- a/source/gui/msgbox.cpp
+++ b/source/gui/msgbox.cpp
@@ -1294,8 +1294,10 @@ namespace nana
         min_width_entry_field_pixels_ = pixels;
 	}
 
+#ifndef _nana_cxx_folding_expression
 	void inputbox::_m_fetch_args(std::vector<abstract_content*>&)
 	{}
+#endif
 
 	bool inputbox::_m_open(std::vector<abstract_content*>& contents, bool modal)
 	{