Set project to C++17

vcc-base.props set to C++17

core/utils/winapi.cpp modified to demonstrate C++17 namespace nesting
and to fix STL4017.  Still don't like the winapi.cpp filename but that
perhaps is for another commit.

Author: ejaquay

README.md

@@ -28,7 +28,9 @@ VCC is written in C++ and Microsoft Visual Studio 2022 Community is used to buil
 
 To build VCC from the command line, launch the "Developer Command Prompt for VS 2022". From there, change to the directory containing the VCC sources and type "Build" or "BuildClean".
 
-Within Visual Studio, the "Release" and "Debug" configurations build VCC binaries that will run on current Windows versions. The "Legacy" configuration builds binaries that will run on Windows XP. "Legacy" uses the v121_xp build tools from which you need to find and install.  Maintaining a VCC version that will run on XP is becoming difficult and it is likely a future version will no longer support it 
+Within Visual Studio, the "Release" and "Debug" configurations build VCC binaries that will run on current Windows versions. The "Legacy" configuration builds binaries that will run on Windows XP. "Legacy" uses the v141_xp build tools from which you need to find and install.  Maintaining a VCC version that will run on XP is becoming difficult and it is likely a future version will no longer support it.
+
+Portions of VCC code have been modified to use features of the C++17 standard.
 
 ## Contributing to VCC
 We welcome patches and code contributions that are consistent with our goals. Please comment your code well and add your name if you want credit for your work.

libcommon/src/core/utils/winapi.cpp

@@ -15,23 +15,36 @@
 //	You should have received a copy of the GNU General Public License along with
 //	VCC (Virtual Color Computer). If not, see <http://www.gnu.org/licenses/>.
 ////////////////////////////////////////////////////////////////////////////////
-#include <vcc/core/utils/winapi.h>
-#include <codecvt>
 
+#include <vcc/core/utils/winapi.h>
+#include <string>
+#include <windows.h>
 
-namespace vcc { namespace core { namespace utils
+namespace vcc::core::utils
 {
-
 	LIBCOMMON_EXPORT std::string load_string(HINSTANCE instance, UINT id)
 	{
-		LPWSTR buffer_ptr = nullptr;
-		const auto buffer_length(LoadStringW(instance, id, reinterpret_cast<LPWSTR>(&buffer_ptr), 0));
-		if (buffer_length < 1 || buffer_ptr == nullptr)
-		{
-			return { };
-		}
+		// Get len of string to load
+		const int length = LoadStringW(instance, id, nullptr, 0);
+		if (length == 0)
+			return {};
+
+		// Copy load string to wide_str
+		std::wstring wide_str(length, L'\0');
+		const int copied = LoadStringW(instance, id, wide_str.data(), length + 1);
+		if (copied == 0)
+			return {};
+
+		// Get len of string when converted
+		const int utf8_len = WideCharToMultiByte(CP_UTF8, 0, wide_str.data(), copied, nullptr, 0, nullptr, nullptr);
+			if (utf8_len == 0)
+			return {};
+
+		// Convert string from wide_str to utf8_str
+		std::string utf8_str(utf8_len, '\0');
+		WideCharToMultiByte(CP_UTF8, 0, wide_str.data(), copied, utf8_str.data(), utf8_len, nullptr, nullptr);
 
-		return std::wstring_convert<std::codecvt_utf8<wchar_t>>().to_bytes(buffer_ptr, buffer_ptr + buffer_length);
+		return utf8_str;
 	}
+}
 
-} } }

vcc-base.props

@@ -9,6 +9,7 @@
   </PropertyGroup>
   <ItemDefinitionGroup>
     <ClCompile>
+      <LanguageStandard>stdcpp17</LanguageStandard>
       <WarningLevel>Level3</WarningLevel>
       <PreprocessorDefinitions>_CRT_SECURE_NO_WARNINGS;_WINDOWS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <BrowseInformation>true</BrowseInformation>
@@ -20,4 +21,5 @@
     </Link>
   </ItemDefinitionGroup>
   <ItemGroup />
-</Project>
+</Project>
+