Initial addition of native visualizer, to improve debugging experienc…

…e. (#3906)

vcpkg.natvis

@@ -0,0 +1,35 @@
+<?xml version="1.0" encoding="utf-8"?>
+<AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
+	<Type Name="vcpkg::ErrorHolder&lt;std::error_code&gt;">
+		<DisplayString Condition="m_err._Myval!=0">{m_err}</DisplayString>
+		<DisplayString Condition="m_err._Myval==0"></DisplayString>
+	</Type>
+	<Type Name="vcpkg::ErrorHolder&lt;*&gt;">
+		<DisplayString Condition="m_is_error==true">{m_err}</DisplayString>
+		<DisplayString Condition="m_is_error==false"></DisplayString>
+	</Type>
+	<Type Name="vcpkg::ExpectedT&lt;*,std::error_code&gt;">
+		<DisplayString Condition="m_s.m_err._Myval==0">val: {m_t}</DisplayString>
+		<DisplayString Condition="m_s.m_err._Myval!=0">err: {m_s}</DisplayString>
+	</Type>
+	<Type Name="vcpkg::ExpectedT&lt;*,*&gt;">
+		<DisplayString Condition="m_s.m_is_error==false">val: {m_t}</DisplayString>
+		<DisplayString Condition="m_s.m_is_error==true">err: {m_s}</DisplayString>
+	</Type>
+	<Type Name="vcpkg::Optional&lt;*&gt;">
+		<DisplayString Condition="m_base.m_is_present==true">{m_base.m_t}</DisplayString>
+		<DisplayString Condition="m_base.m_is_present==false">empty</DisplayString>
+	</Type>
+	<Type Name="vcpkg::TripletInstance">
+		<DisplayString>{*(std::string*)this}</DisplayString>
+	</Type>
+	<Type Name="vcpkg::Triplet">
+		<DisplayString>{m_instance}</DisplayString>
+	</Type>
+	<Type Name="vcpkg::StringLiteral">
+		<DisplayString>{m_cstr}</DisplayString>
+	</Type>
+	<Type Name="std::experimental::filesystem::v1::path">
+		<DisplayString>{_Mystr}</DisplayString>
+	</Type>
+</AutoVisualizer>

vcpkg.sln

@@ -47,6 +47,11 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "cmake", "cmake", "{A0122231
 		..\scripts\cmake\vcpkg_install_meson.cmake = ..\scripts\cmake\vcpkg_install_meson.cmake
 	EndProjectSection
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution Items", "{BCE555DF-F471-4ACC-98E5-76CBE8E8F79E}"
+	ProjectSection(SolutionItems) = preProject
+		vcpkg.natvis = vcpkg.natvis
+	EndProjectSection
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|x64 = Debug|x64