use std::string_view

source/deploy.cpp

@@ -175,12 +175,12 @@ namespace nana
 		return str;
 	}
 
-	std::string to_utf8(const std::wstring& text)
+#ifdef _nana_std_has_string_view
+	std::string to_utf8(std::wstring_view text)
 	{
-		return ::nana::charset(text).to_bytes(::nana::unicode::utf8);
+		return ::nana::charset(std::wstring{text}).to_bytes(::nana::unicode::utf8);
 	}
 
-#ifdef _nana_std_has_string_view
 	std::wstring to_wstring(std::string_view utf8_str)
 	{
 		if (utf8_str.empty())
@@ -189,6 +189,11 @@ namespace nana
 		return ::nana::charset(std::string{ utf8_str.data(), utf8_str.size() }, unicode::utf8);
 	}
 #else
+	std::string to_utf8(const std::wstring& text)
+	{
+		return ::nana::charset(text).to_bytes(::nana::unicode::utf8);
+	}
+
 	std::wstring to_wstring(const std::string& utf8_str)
 	{
 		return ::nana::charset(utf8_str, ::nana::unicode::utf8);

source/gui/widgets/combox.cpp

@@ -1,7 +1,7 @@
 /*
  *	A Combox Implementation
  *	Nana C++ Library(http://www.nanapro.org)
- *	Copyright(C) 2003-2017 Jinhao(cnjinhao@hotmail.com)
+ *	Copyright(C) 2003-2018 Jinhao(cnjinhao@hotmail.com)
  *
  *	Distributed under the Boost Software License, Version 1.0.
  *	(See accompanying file LICENSE_1_0.txt or copy at
@@ -823,6 +823,14 @@ namespace nana
 				}
 
 				/// Behavior of Iterator's value_type
+#ifdef _nana_std_has_string_view
+				bool item_proxy::operator == (::std::string_view s) const
+				{
+					if (pos_ == nana::npos)
+						return false;
+					return (impl_->at(pos_).item_text == s);
+				}
+#else
 				bool item_proxy::operator == (const ::std::string& s) const
 				{
 					if (pos_ == nana::npos)
@@ -836,6 +844,7 @@ namespace nana
 						return false;
 					return (impl_->at(pos_).item_text == s);
 				}
+#endif
 
 
 				/// Behavior of Iterator

source/gui/widgets/listbox.cpp

@@ -4825,6 +4825,17 @@ namespace nana
 				}
 
 				//Behavior of Iterator's value_type
+#ifdef _nana_std_has_string_view
+				bool item_proxy::operator==(std::string_view sv) const
+				{
+					return (text(0) == sv);
+				}
+
+				bool item_proxy::operator==(std::wstring_view sv) const
+				{
+					return (text(0) == to_utf8(sv));
+				}
+#else
 				bool item_proxy::operator==(const char * s) const
 				{
 					return this->operator==(std::string(s));
@@ -4844,6 +4855,7 @@ namespace nana
 				{
 					return (text(0) == to_utf8(s));
 				}
+#endif
 
 				item_proxy & item_proxy::operator=(const item_proxy& rhs)
 				{