Adding new string conversion overloads

[a|w|t|utf8]_from_[a|w|t|utf8_]string(xyz.c_str()) seems to be common enough to justify overloads.  Also, I'm explicitly assuming that it is legal to override the NUL pointer within a C++ basic_string (e.g. - s[s.size()] = '\0').  As far as I can tell, this seems to be legal - please don't shoot if I am wrong.

src/osd/modules/debugger/win/consolewininfo.cpp

@@ -43,7 +43,7 @@ consolewin_info::consolewin_info(debugger_windows_interface &debugger) :
 			m_devices_menu = CreatePopupMenu();
 			for (device_image_interface &img : iter)
 			{
-				auto tc_buf = tstring_from_utf8(string_format("%s : %s", img.device().name(), img.exists() ? img.filename() : "[no image]").c_str());
+				tstring tc_buf = tstring_from_utf8(string_format("%s : %s", img.device().name(), img.exists() ? img.filename() : "[no image]"));
 				AppendMenu(m_devices_menu, MF_ENABLED, 0, tc_buf.c_str());
 			}
 			AppendMenu(GetMenu(window()), MF_ENABLED | MF_POPUP, (UINT_PTR)m_devices_menu, TEXT("Images"));
@@ -189,7 +189,7 @@ void consolewin_info::update_menu()
 				AppendMenu(devicesubmenu, flags_for_exists, new_item + DEVOPTION_CASSETTE_FASTFORWARD, TEXT("Fast Forward"));
 			}
 
-			auto tc_buf = tstring_from_utf8(string_format("%s :%s", img.device().name(), img.exists() ? img.filename() : "[empty slot]").c_str());
+			tstring tc_buf = tstring_from_utf8(string_format("%s :%s", img.device().name(), img.exists() ? img.filename() : "[empty slot]"));
 			ModifyMenu(m_devices_menu, cnt, MF_BYPOSITION | MF_POPUP, (UINT_PTR)devicesubmenu, tc_buf.c_str());
 
 			cnt++;
@@ -214,7 +214,7 @@ bool consolewin_info::handle_command(WPARAM wparam, LPARAM lparam)
 					std::string filter;
 					build_generic_filter(img, false, filter);
 					{
-						auto t_filter = tstring_from_utf8(filter.c_str());
+						tstring t_filter = tstring_from_utf8(filter);
 
 						// convert a pipe-char delimited string into a NUL delimited string
 						for (int i = 0; t_filter[i] != '\0'; i++)
@@ -252,7 +252,7 @@ bool consolewin_info::handle_command(WPARAM wparam, LPARAM lparam)
 					std::string filter;
 					build_generic_filter(img, true, filter);
 					{
-						auto t_filter = tstring_from_utf8(filter.c_str());
+						tstring t_filter = tstring_from_utf8(filter);
 						// convert a pipe-char delimited string into a NUL delimited string
 						for (int i = 0; t_filter[i] != '\0'; i++)
 						{

src/osd/modules/file/windir.cpp

@@ -112,7 +112,7 @@ bool win_directory::open_impl(std::string const &dirname)
 	std::string dirfilter = string_format("%s\\*.*", dirname);
 
 	// convert the path to TCHARs
-	auto t_dirfilter = tstring_from_utf8(dirfilter.c_str());
+	tstring t_dirfilter = tstring_from_utf8(dirfilter);
 
 	// attempt to find the first file
 	m_find = FindFirstFileEx(t_dirfilter.c_str(), FindExInfoStandard, &m_data, FindExSearchNameMatch, nullptr, 0);

src/osd/modules/file/winfile.cpp

@@ -173,7 +173,7 @@ osd_file::error osd_file::open(std::string const &orig_path, UINT32 openflags, p
 		return win_open_ptty(path, openflags, file, filesize);
 
 	// convert path to TCHAR
-	auto t_path = tstring_from_utf8(path.c_str());
+	tstring t_path = tstring_from_utf8(path);
 
 	// convert the path into something Windows compatible (the actual interesting part appears
 	// to have been commented out???)
@@ -274,7 +274,7 @@ osd_file::error osd_file::openpty(ptr &file, std::string &name)
 
 osd_file::error osd_file::remove(std::string const &filename)
 {
-	auto tempstr = tstring_from_utf8(filename.c_str());
+	tstring tempstr = tstring_from_utf8(filename);
 
 	error filerr = error::NONE;
 	if (!DeleteFile(tempstr.c_str()))
@@ -338,7 +338,7 @@ int osd_get_physical_drive_geometry(const char *filename, UINT32 *cylinders, UIN
 std::unique_ptr<osd::directory::entry> osd_stat(const std::string &path)
 {
 	// convert the path to TCHARs
-	auto t_path = tstring_from_utf8(path.c_str());
+	tstring t_path = tstring_from_utf8(path);
 
 	// is this path a root directory (e.g. - C:)?
 	WIN32_FIND_DATA find_data;
@@ -382,7 +382,7 @@ std::unique_ptr<osd::directory::entry> osd_stat(const std::string &path)
 osd_file::error osd_get_full_path(std::string &dst, std::string const &path)
 {
 	// convert the path to TCHARs
-	auto t_path = tstring_from_utf8(path.c_str());
+	tstring t_path = tstring_from_utf8(path);
 
 	// cannonicalize the path
 	TCHAR buffer[MAX_PATH];
@@ -402,7 +402,7 @@ osd_file::error osd_get_full_path(std::string &dst, std::string const &path)
 
 bool osd_is_absolute_path(std::string const &path)
 {
-	auto t_path = tstring_from_utf8(path.c_str());
+	tstring t_path = tstring_from_utf8(path);
 	return !PathIsRelative(t_path.c_str());
 }
 

src/osd/modules/file/winptty.cpp

@@ -87,7 +87,7 @@ bool win_check_ptty_path(std::string const &path)
 
 osd_file::error win_open_ptty(std::string const &path, std::uint32_t openflags, osd_file::ptr &file, std::uint64_t &filesize)
 {
-	auto t_name = tstring_from_utf8(path.c_str());
+	tstring t_name = tstring_from_utf8(path);
 
 	HANDLE pipe = CreateNamedPipe(t_name.c_str(), PIPE_ACCESS_DUPLEX, PIPE_TYPE_BYTE | PIPE_READMODE_BYTE | PIPE_NOWAIT, 1, 32, 32, 0, nullptr);
 

src/osd/modules/font/font_windows.cpp

@@ -85,7 +85,7 @@ bool osd_font_windows::open(std::string const &font_path, std::string const &_na
 	logfont.lfPitchAndFamily = DEFAULT_PITCH | FF_DONTCARE;
 
 	// copy in the face name
-	std::basic_string<TCHAR> face = tstring_from_utf8(name.c_str());
+	tstring face = tstring_from_utf8(name);
 	_tcsncpy(logfont.lfFaceName, face.c_str(), ARRAY_LENGTH(logfont.lfFaceName));
 	logfont.lfFaceName[sizeof(logfont.lfFaceName) / sizeof(TCHAR)-1] = 0;
 

src/osd/modules/lib/osdlib_win32.cpp

@@ -367,7 +367,7 @@ protected:
 
 		for (auto const &library : m_libraries)
 		{
-			auto tempstr = tstring_from_utf8(library.c_str());
+			tstring tempstr = tstring_from_utf8(library);
 			HMODULE module = load_library(tempstr.c_str());
 
 			if (module != nullptr)

src/osd/strconv.cpp

@@ -16,6 +16,36 @@
 #include "strconv.h"
 
 #if defined(SDLMAME_WIN32) || defined(OSD_WINDOWS)
+//============================================================
+//  astring_from_wstring
+//============================================================
+
+static std::string &astring_from_wstring(std::string &dst, const std::wstring &wstring)
+{
+	// convert UTF-16 to "ANSI code page" string
+	int char_count = WideCharToMultiByte(CP_ACP, 0, wstring.c_str(), wstring.size() + 1, nullptr, 0, nullptr, nullptr);
+	dst.resize(char_count - 1);
+	WideCharToMultiByte(CP_ACP, 0, wstring.c_str(), wstring.size(), &dst[0], char_count, nullptr, nullptr);
+
+	return dst;
+}
+
+
+//============================================================
+//  astring_from_utf8
+//============================================================
+
+std::string &astring_from_utf8(std::string &dst, const std::string &s)
+{
+	// convert MAME string (UTF-8) to UTF-16
+	std::wstring wstring = wstring_from_utf8(s);
+
+	// convert UTF-16 to "ANSI code page" string
+	return astring_from_wstring(dst, wstring);
+}
+
+
+
 //============================================================
 //  astring_from_utf8
 //============================================================
@@ -23,14 +53,22 @@
 std::string &astring_from_utf8(std::string &dst, const char *s)
 {
 	// convert MAME string (UTF-8) to UTF-16
-	std::basic_string<WCHAR> wstring = wstring_from_utf8(s);
+	std::wstring wstring = wstring_from_utf8(s);
 
 	// convert UTF-16 to "ANSI code page" string
-	int char_count = WideCharToMultiByte(CP_ACP, 0, wstring.c_str(), wstring.size(), nullptr, 0, nullptr, nullptr);
-	dst.resize(char_count);
-	WideCharToMultiByte(CP_ACP, 0, wstring.c_str(), wstring.size(), &dst[0], char_count, nullptr, nullptr);
+	return astring_from_wstring(dst, wstring);
+}
 
-	return dst;
+
+//============================================================
+//  astring_from_utf8
+//============================================================
+
+std::string astring_from_utf8(const std::string &s)
+{
+	std::string result;
+	astring_from_utf8(result, s);
+	return result;
 }
 
 
@@ -46,6 +84,22 @@ std::string astring_from_utf8(const char *s)
 }
 
 
+//============================================================
+//  utf8_from_astring
+//============================================================
+
+std::string &utf8_from_astring(std::string &dst, const std::string &s)
+{
+	// convert "ANSI code page" string to UTF-16
+	int char_count = MultiByteToWideChar(CP_ACP, 0, s.c_str(), s.size() + 1, nullptr, 0);
+	std::wstring wstring(char_count - 1, 0);
+	MultiByteToWideChar(CP_ACP, 0, s.c_str(), s.size() + 1, &wstring[0], char_count - 1);
+
+	// convert UTF-16 to MAME string (UTF-8)
+	return utf8_from_wstring(dst, wstring);
+}
+
+
 //============================================================
 //  utf8_from_astring
 //============================================================
@@ -58,7 +112,19 @@ std::string &utf8_from_astring(std::string &dst, const CHAR *s)
 	MultiByteToWideChar(CP_ACP, 0, s, -1, &wstring[0], char_count - 1);
 
 	// convert UTF-16 to MAME string (UTF-8)
-	return utf8_from_wstring(dst, wstring.c_str());
+	return utf8_from_wstring(dst, wstring);
+}
+
+
+//============================================================
+//  utf8_from_astring
+//============================================================
+
+std::string utf8_from_astring(const std::string &s)
+{
+	std::string result;
+	utf8_from_astring(result, s);
+	return result;
 }
 
 
@@ -74,6 +140,21 @@ std::string utf8_from_astring(const CHAR *s)
 }
 
 
+//============================================================
+//  wstring_from_utf8
+//============================================================
+
+std::wstring &wstring_from_utf8(std::wstring &dst, const std::string &s)
+{
+	// convert MAME string (UTF-8) to UTF-16
+	int char_count = MultiByteToWideChar(CP_UTF8, 0, s.c_str(), s.size() + 1, nullptr, 0);
+	dst.resize(char_count - 1);
+	MultiByteToWideChar(CP_UTF8, 0, s.c_str(), s.size() + 1, &dst[0], char_count - 1);
+
+	return dst;
+}
+
+
 //============================================================
 //  wstring_from_utf8
 //============================================================
@@ -89,6 +170,18 @@ std::wstring &wstring_from_utf8(std::wstring &dst, const char *s)
 }
 
 
+//============================================================
+//  wstring_from_utf8
+//============================================================
+
+std::wstring wstring_from_utf8(const std::string &s)
+{
+	std::wstring result;
+	wstring_from_utf8(result, s);
+	return result;
+}
+
+
 //============================================================
 //  wstring_from_utf8
 //============================================================
@@ -101,6 +194,21 @@ std::wstring wstring_from_utf8(const char *s)
 }
 
 
+//============================================================
+//  utf8_from_wstring
+//============================================================
+
+std::string &utf8_from_wstring(std::string &dst, const std::wstring &s)
+{
+	// convert UTF-16 to MAME string (UTF-8)
+	int char_count = WideCharToMultiByte(CP_UTF8, 0, s.c_str(), s.size() + 1, nullptr, 0, nullptr, nullptr);
+	dst.resize(char_count - 1);
+	WideCharToMultiByte(CP_UTF8, 0, s.c_str(), -1, &dst[0], char_count - 1, nullptr, nullptr);
+
+	return dst;
+}
+
+
 //============================================================
 //  utf8_from_wstring
 //============================================================
@@ -116,6 +224,18 @@ std::string &utf8_from_wstring(std::string &dst, const WCHAR *s)
 }
 
 
+//============================================================
+//  utf8_from_wstring
+//============================================================
+
+std::string utf8_from_wstring(const std::wstring &s)
+{
+	std::string result;
+	utf8_from_wstring(result, s);
+	return result;
+}
+
+
 //============================================================
 //  utf8_from_wstring
 //============================================================

src/osd/strconv.h

@@ -25,22 +25,30 @@
 
 #include <windows.h>
 
-// the result of these functions has to be released with osd_free()
-
+std::string astring_from_utf8(const std::string &s);
 std::string astring_from_utf8(const char *s);
+std::string &astring_from_utf8(std::string &dst, std::string &s);
 std::string &astring_from_utf8(std::string &dst, const char *s);
+std::string utf8_from_astring(const std::string &s);
 std::string utf8_from_astring(const CHAR *s);
+std::string &utf8_from_astring(std::string &dst, const std::string &s);
 std::string &utf8_from_astring(std::string &dst, const CHAR *s);
 
+std::wstring wstring_from_utf8(const std::string &s);
 std::wstring wstring_from_utf8(const char *s);
+std::wstring &wstring_from_utf8(std::wstring &dst, std::string &s);
 std::wstring &wstring_from_utf8(std::wstring &dst, const char *s);
+std::string utf8_from_wstring(const std::wstring &s);
 std::string utf8_from_wstring(const WCHAR *s);
+std::string &utf8_from_wstring(std::string &dst, const std::wstring &s);
 std::string &utf8_from_wstring(std::string &dst, const WCHAR *s);
 
 #ifdef UNICODE
+typedef std::wstring tstring;
 #define tstring_from_utf8   wstring_from_utf8
 #define utf8_from_tstring   utf8_from_wstring
 #else // !UNICODE
+typedef std::string tstring;
 #define tstring_from_utf8   astring_from_utf8
 #define utf8_from_tstring   utf8_from_astring
 #endif // UNICODE

src/osd/windows/winutil.cpp

@@ -106,7 +106,7 @@ void osd_subst_env(std::string &dst, const std::string &src)
 {
 	TCHAR buffer[MAX_PATH];
 
-	auto t_src = tstring_from_utf8(src.c_str());
+	tstring t_src = tstring_from_utf8(src);
 	ExpandEnvironmentStrings(t_src.c_str(), buffer, ARRAY_LENGTH(buffer));
 	utf8_from_tstring(dst, buffer);
 }