diff --git a/src/CppParser/Parser.cpp b/src/CppParser/Parser.cpp
index b7d1d895..dd69b553 100644
--- a/src/CppParser/Parser.cpp
+++ b/src/CppParser/Parser.cpp
@@ -157,6 +157,8 @@ Parser::Parser(CppParserOptions* Opts)
 {
     supportedStdTypes.insert("allocator");
     supportedStdTypes.insert("basic_string");
+    supportedStdTypes.insert("optional");
+    supportedStdTypes.insert("vector");
 }
 
 LayoutField Parser::WalkVTablePointer(Class* Class,
@@ -1011,15 +1013,44 @@ bool Parser::IsSupported(const clang::CXXMethodDecl* MD)
 {
     using namespace clang;
 
-    return !c->getSourceManager().isInSystemHeader(MD->getBeginLoc()) ||
-        (isa<CXXConstructorDecl>(MD) && MD->getNumParams() == 0) ||
-        isa<CXXDestructorDecl>(MD) ||
-        (MD->getDeclName().isIdentifier() &&
-         ((MD->getName() == "data" && MD->getNumParams() == 0 && MD->isConst()) ||
-          (MD->getName() == "assign" && MD->getNumParams() == 1 &&
-           MD->parameters()[0]->getType()->isPointerType())) &&
-         supportedStdTypes.find(MD->getParent()->getName().str()) !=
-            supportedStdTypes.end());
+    if (!c->getSourceManager().isInSystemHeader(MD->getBeginLoc()))
+        return true;
+
+    if (isa<CXXConstructorDecl>(MD))
+        return MD->getNumParams() == 0;
+
+    if (isa<CXXDestructorDecl>(MD))
+        return true;
+
+    if (!MD->getDeclName().isIdentifier())
+        return false;
+
+    if (supportedStdTypes.find(MD->getParent()->getName().str()) == supportedStdTypes.end())
+        return false;
+
+    switch (MD->getNumParams())
+    {
+        case 0:
+        {
+            if (!MD->isConst())
+                return  false;
+
+            return MD->getName() == "data" ||
+                MD->getName() == "has_value" ||
+                MD->getName() == "value";
+        }
+        case 1:
+        {
+            if (!MD->parameters()[0]->getType()->isPointerType())
+                return false;
+
+            return MD->getName() == "assign";
+        }
+        default:
+        {
+            return false;
+        }
+    }
 }
 
 static RecordArgABI GetRecordArgABI(
diff --git a/src/Generator/Passes/IgnoreSystemDeclarationsPass.cs b/src/Generator/Passes/IgnoreSystemDeclarationsPass.cs
index 1f0a7bf9..4d46f654 100644
--- a/src/Generator/Passes/IgnoreSystemDeclarationsPass.cs
+++ b/src/Generator/Passes/IgnoreSystemDeclarationsPass.cs
@@ -44,12 +44,25 @@ namespace CppSharp.Passes
                 case "basic_string":
                 case "allocator":
                 case "char_traits":
+                    @class.GenerationKind = GenerationKind.Generate;
+                    foreach (var specialization in from s in @class.Specializations
+                             where !s.Arguments.Any(a =>
+                                 s.UnsupportedTemplateArgument(a, Context.TypeMaps))
+                             let arg = s.Arguments[0].Type.Type.Desugar()
+                             where arg.IsPrimitiveType(PrimitiveType.Char)
+                             select s)
+                    {
+                        specialization.GenerationKind = GenerationKind.Generate;
+                        InternalizeSpecializationsInFields(specialization);
+                    }
+                    break;
+
+                case "optional":
+                case "vector":
                     @class.GenerationKind = GenerationKind.Generate;
                     foreach (var specialization in from s in @class.Specializations
                                                    where !s.Arguments.Any(a =>
                                                        s.UnsupportedTemplateArgument(a, Context.TypeMaps))
-                                                   let arg = s.Arguments[0].Type.Type.Desugar()
-                                                   where arg.IsPrimitiveType(PrimitiveType.Char)
                                                    select s)
                     {
                         specialization.GenerationKind = GenerationKind.Generate;
diff --git a/src/Generator/Passes/SymbolsCodeGenerator.cs b/src/Generator/Passes/SymbolsCodeGenerator.cs
index 1b5bf760..397c17f8 100644
--- a/src/Generator/Passes/SymbolsCodeGenerator.cs
+++ b/src/Generator/Passes/SymbolsCodeGenerator.cs
@@ -34,6 +34,7 @@ namespace CppSharp.Passes
                 WriteLine("#define _LIBCPP_HIDE_FROM_ABI");
                 NewLine();
                 WriteLine("#include <string>");
+                WriteLine("#include <optional>");
             }
             else
                 foreach (var header in TranslationUnit.Module.Headers)