Add project files.

library_cpp.sln

@@ -0,0 +1,31 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.5.33424.131
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "library_cpp", "library_cpp.vcxproj", "{6DD87860-E42C-4F71-8B30-12FF5200CF8C}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|x64 = Debug|x64
+		Debug|x86 = Debug|x86
+		Release|x64 = Release|x64
+		Release|x86 = Release|x86
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{6DD87860-E42C-4F71-8B30-12FF5200CF8C}.Debug|x64.ActiveCfg = Debug|x64
+		{6DD87860-E42C-4F71-8B30-12FF5200CF8C}.Debug|x64.Build.0 = Debug|x64
+		{6DD87860-E42C-4F71-8B30-12FF5200CF8C}.Debug|x86.ActiveCfg = Debug|Win32
+		{6DD87860-E42C-4F71-8B30-12FF5200CF8C}.Debug|x86.Build.0 = Debug|Win32
+		{6DD87860-E42C-4F71-8B30-12FF5200CF8C}.Release|x64.ActiveCfg = Release|x64
+		{6DD87860-E42C-4F71-8B30-12FF5200CF8C}.Release|x64.Build.0 = Release|x64
+		{6DD87860-E42C-4F71-8B30-12FF5200CF8C}.Release|x86.ActiveCfg = Release|Win32
+		{6DD87860-E42C-4F71-8B30-12FF5200CF8C}.Release|x86.Build.0 = Release|Win32
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {A71AFAA4-6C4E-4879-9DCB-BE1B90C8CA96}
+	EndGlobalSection
+EndGlobal