using C++17 emplace return type

include/nana/c++defines.hpp

@@ -220,14 +220,14 @@
 #endif
 
 #undef _nana_std_has_string_view
-#undef _nana_std_has_returnable_emplace_back
+#undef _nana_std_has_emplace_return_type
 #if ((defined(_MSC_VER) && (_MSC_VER >= 1912) && defined(_MSVC_LANG) && _MSVC_LANG >= 201703)) ||				\
 	((__cplusplus >= 201703L) && \
 		(defined(__clang__) && (__clang_major__ * 100 + __clang_minor__ >= 400) ||		\
 		(!defined(__clang__) && defined(__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 701))) \
 	)
 #	define _nana_std_has_string_view
-#	define _nana_std_has_returnable_emplace_back
+#	define _nana_std_has_emplace_return_type
 #endif
 
 

source/basic_types.cpp

@@ -186,10 +186,12 @@ namespace nana
 				throw std::invalid_argument(excpt_what);
 			
 			std::vector<std::string> rgb;
-
+#ifdef _nana_std_has_emplace_return_type
+			auto const is_real = (rgb.emplace_back(i->str()).back() == '%');
+#else
 			rgb.emplace_back(i->str());
-
 			const bool is_real = (rgb.back().back() == '%');
+#endif
 			pat.assign(is_real ? "(\\d*\\.)?\\d+\\%" : "\\d+");
 
 			for (++i; i != end; ++i)
@@ -275,9 +277,13 @@ namespace nana
 		{
 			std::vector<std::string> rgb;
 
+#ifdef _nana_std_has_emplace_return_type
+			auto const is_real = (rgb.emplace_back(std::move(str)).back() == '%');
+#else
 			rgb.emplace_back(std::move(str));
 
 			const bool is_real = (rgb.back().back() == '%');
+#endif
 
 			for (int i = 0; i < 2; ++i)
 			{

source/gui/detail/window_manager.cpp

@@ -85,8 +85,12 @@ namespace nana
 				}
 			}
 
+#ifdef _nana_std_has_emplace_return_type
+			auto & rep = impl_->base.emplace_back();
+#else
 			impl_->base.emplace_back();
 			auto & rep = impl_->base.back();
+#endif
 			rep.handle = wd;
 			rep.keys.emplace_back(key);
 
@@ -242,8 +246,12 @@ namespace detail
 					return kv.second;
 			}
 
+#ifdef _nana_std_has_emplace_return_type
+			return table_.emplace_back(key).second;
+#else
 			table_.emplace_back(key);
 			return table_.back().second;
+#endif
 		}
 
 		iterator find(const Key& key)

source/gui/place.cpp

@@ -742,8 +742,14 @@ namespace nana
 
 		void _m_add_agent(const detail::place_agent& ag) override
 		{
+#ifdef _nana_std_has_emplace_return_type
+			this->operator<<(
+					widgets_.emplace_back(ag.create(place_ptr_->window_handle()))->handle()
+				);
+#else
 			widgets_.emplace_back(ag.create(place_ptr_->window_handle()));
 			this->operator<<(widgets_.back()->handle());
+#endif
 		}
 	public:
 		division* attached{ nullptr };

source/gui/place_parts.hpp

@@ -436,10 +436,13 @@ namespace nana
 						caption_.caption(wdg->caption());
 					}
 
-					panels_.emplace_back();
 					auto wdg_ptr = wdg.get();
+#ifdef _nana_std_has_emplace_return_type
+					panels_.emplace_back().widget_ptr = std::move(wdg);
+#else
+					panels_.emplace_back();
 					panels_.back().widget_ptr.swap(wdg);
-
+#endif
 					for (auto & pn : panels_)
 					{
 						if (pn.widget_ptr)

source/gui/widgets/group.cpp

@@ -136,8 +136,12 @@ namespace nana{
 	{
 		_THROW_IF_EMPTY()
 
+#ifdef _nana_std_has_emplace_return_type
+		auto & opt = impl_->options.emplace_back(new checkbox{ handle() });
+#else
 		impl_->options.emplace_back(new checkbox(handle()));
 		auto & opt = impl_->options.back();
+#endif
 		opt->transparent(true);
 		opt->caption(std::move(text));
 		impl_->place_content[field_options] << *opt;

source/gui/widgets/label.cpp

@@ -226,8 +226,12 @@ namespace nana
 				{
 					if(fbp->target.size() || fbp->url.size())
 					{
+#ifdef _nana_std_has_emplace_return_type
+						auto & tr = traceable_.emplace_back();
+#else
 						traceable_.emplace_back();
 						auto & tr = traceable_.back();
+#endif
 						tr.r.x = x;
 						tr.r.y = y;
 						tr.r.dimension(sz);
@@ -398,7 +402,7 @@ namespace nana
 						//make a visual line for existing vsline elements
 						if (text_pos)
 						{
-#ifdef _nana_std_has_returnable_emplace_back
+#ifdef _nana_std_has_emplace_return_type
 							auto & vsline = rs.vslines.emplace_back();
 #else
 							rs.vslines.emplace_back();
@@ -449,7 +453,7 @@ namespace nana
 								if (text_begin + sub_text_len < data->text().size())
 								{
 									//make a new visual line
-#ifdef _nana_std_has_returnable_emplace_back
+#ifdef _nana_std_has_emplace_return_type
 									auto & vsline = rs.vslines.emplace_back();
 #else
 									rs.vslines.emplace_back();
@@ -483,7 +487,7 @@ namespace nana
 
 					if (!vsline_elements.empty())
 					{
-#ifdef _nana_std_has_returnable_emplace_back
+#ifdef _nana_std_has_emplace_return_type
 						auto & vsline = rs.vslines.emplace_back();
 #else
 						rs.vslines.emplace_back();
@@ -515,14 +519,14 @@ namespace nana
 #endif
 
 					text_px = 0;
-					for (std::size_t i = 0; i < text.size(); ++i)
+					for (unsigned i = 0; i < text.size(); ++i)
 					{
 						if (text_px + pxbuf[i] > limited_width_px)
 							return i;
 
 						text_px += pxbuf[i];
 					}
-					return text.size();
+					return static_cast<unsigned>(text.size());
 				}
 
 				bool _m_foreach_visual_line(graph_reference graph, render_status& rs)
@@ -542,7 +546,7 @@ namespace nana
 						}
 
 						++rs.index;	//next line index
-						rs.pos.y += vsline.extent_height_px;
+						rs.pos.y += static_cast<int>(vsline.extent_height_px);
 
 						if (rs.pos.y > bottom)
 							return false;

source/gui/widgets/listbox.cpp

@@ -312,8 +312,12 @@ namespace nana
 
 				size_type create(essence* ess, native_string_type&& text, unsigned pixels)
 				{
+#ifdef _nana_std_has_emplace_return_type
+					return cont_.emplace_back(ess, std::move(text), pixels, static_cast<size_type>(cont_.size())).index;
+#else
 					cont_.emplace_back(ess, std::move(text), pixels, static_cast<size_type>(cont_.size()));
                     return cont_.back().index;
+#endif
 				}
 
 				void clear()
@@ -1023,9 +1027,15 @@ namespace nana
 						}
 					}
 
+#ifdef _nana_std_has_emplace_return_type
+					auto & last_cat = categories_.emplace_back();
+					last_cat.key_ptr = ptr;
+					return &last_cat;
+#else
 					categories_.emplace_back();
 					categories_.back().key_ptr = ptr;
 					return &(categories_.back());
+#endif
 				}
                 
 				/// Inserts a new category at position specified by pos
@@ -1033,8 +1043,12 @@ namespace nana
 				{
 					if (::nana::npos == pos)
 					{
+#ifdef _nana_std_has_emplace_return_type
+						return &categories_.emplace_back(std::move(text));
+#else
 						categories_.emplace_back(std::move(text));
 						return &categories_.back();
+#endif
 					}
 
 					return &(*categories_.emplace(this->get(pos), std::move(text)));
@@ -2622,8 +2636,12 @@ namespace nana
 
 			oresolver& oresolver::operator<<(std::nullptr_t)
 			{
+#ifdef _nana_std_has_emplace_return_type
+				cells_.emplace_back().text.assign(1, wchar_t{});
+#else
 				cells_.emplace_back();
 				cells_.back().text.assign(1, wchar_t(0));	//means invalid cell
+#endif
 				return *this;
 			}
 

source/gui/widgets/menubar.cpp

@@ -89,11 +89,18 @@ namespace nana
 
 					if (shortkey && shortkey < 0x61)
 						shortkey += (0x61 - 0x41);
+
+#ifdef _nana_std_has_emplace_return_type
+					auto & last = items.emplace_back(new item_type{std::move(transformed_text), shortkey, shortkey_pos});
+					API::refresh_window(*widget_ptr);
+					return last->menu_obj;
+#else
 					items.emplace_back(new item_type{ std::move(transformed_text), shortkey, shortkey_pos });
 
 					API::refresh_window(*widget_ptr);
 
 					return this->items.back()->menu_obj;
+#endif
 				}
 				
 				bool cancel()

source/gui/widgets/skeletons/text_editor.cpp

@@ -1009,8 +1009,12 @@ namespace nana{	namespace widgets
 					    auto ki = keywords.schemes.find(ds.scheme);
 					    if ((ki != keywords.schemes.end()) && ki->second)
 					    {
+#ifdef _nana_std_has_emplace_return_type
+							auto & last = entities.emplace_back();
+#else
 							entities.emplace_back();
 							auto & last = entities.back();
+#endif
 							last.begin = c_str + pos;
 							last.end = last.begin + ds.text.size();
 							last.scheme = ki->second.get();

source/gui/widgets/tabbar.cpp

@@ -750,8 +750,8 @@ namespace nana
 				{
 					if((pos == npos) || (pos >= list_.size()))
 					{
+						pos = list_.size();
 						this->list_.emplace_back();
-						pos = list_.size() - 1;
 					}
 					else
 						list_.emplace(iterator_at(pos));

source/unicode_bidi.cpp

@@ -1,4 +1,5 @@
 #include <nana/unicode_bidi.hpp>
+#include <nana/c++defines.hpp>
 
 namespace nana
 {
@@ -611,8 +612,12 @@ namespace nana
 
 		void unicode_bidi::_m_push_entity(const char_type * begin, const char_type *end, unsigned level, bidi_char bidi_char_type)
 		{
+#ifdef _nana_std_has_emplace_return_type
+			auto & e = levels_.emplace_back();
+#else
 			levels_.emplace_back();
 			auto & e = levels_.back();
+#endif
 			e.begin = begin;
 			e.end = end;
 			e.level = level;