diff --git a/src/Diagnostic.cc b/src/Diagnostic.cc
index 46693d2..5712527 100644
--- a/src/Diagnostic.cc
+++ b/src/Diagnostic.cc
@@ -17,8 +17,8 @@ clang::Diagnostic::Diagnostic(clang::TranslationUnit& tu, CXDiagnostic& clang_di
   
   clang::SourceRange range(&location, &location);
   clang::Tokens tokens(&tu, &range);
-  if(tokens.tokens().size()==1) {
-    auto& token=tokens.tokens()[0];
+  if(tokens.size()==1) {
+    auto& token=tokens[0];
     clang::SourceRange range=token.get_source_range(&tu);
     clang::SourceLocation location(&range, false);
     location.get_location_info(NULL, &line, &column, &offset);
diff --git a/src/Tokens.cc b/src/Tokens.cc
index baf70aa..0975a97 100644
--- a/src/Tokens.cc
+++ b/src/Tokens.cc
@@ -8,21 +8,17 @@ clang::Tokens::Tokens(clang::TranslationUnit *tu, clang::SourceRange *range): tu
                  &tokens_,
                  &num_tokens_);
   for (int i = 0; i < num_tokens_; i++) {
-    tks.push_back(clang::Token(tokens_[i]));
+    push_back(clang::Token(tokens_[i]));
   }
 }
 
 clang::Tokens::~Tokens() {
-  clang_disposeTokens(tu.tu_, tokens_, tks.size());
+  clang_disposeTokens(tu.tu_, tokens_, size());
 }
 
-std::vector<clang::Token>& clang::Tokens::tokens() {
-  return tks;
-}
-
-void clang::Tokens::get_token_types(clang::TranslationUnit *tu) {
-  std::vector<CXCursor> clang_cursors(tks.size());
-  clang_annotateTokens(tu->tu_, tokens_, tks.size(), clang_cursors.data());
+void clang::Tokens::update_types(clang::TranslationUnit *tu) {
+  std::vector<CXCursor> clang_cursors(size());
+  clang_annotateTokens(tu->tu_, tokens_, size(), clang_cursors.data());
   
   std::vector<clang::Cursor> cursors;
   for(auto clang_cursor: clang_cursors) {
@@ -30,7 +26,7 @@ void clang::Tokens::get_token_types(clang::TranslationUnit *tu) {
     cursors.back().cursor_=clang_cursor;
   }
   
-  for(int c=0;c<tks.size();c++) {
+  for(int c=0;c<size();c++) {
     auto referenced=clang_getCursorReferenced(clang_cursors[c]);
     if(!clang_Cursor_isNull(referenced)) {
       auto type=clang_getCursorType(referenced);
@@ -38,7 +34,8 @@ void clang::Tokens::get_token_types(clang::TranslationUnit *tu) {
       std::string spelling=clang_getCString(cxstr);
       clang_disposeString(cxstr);
       std::string auto_end="";
-      if(spelling.size()>=4 && spelling.substr(0, 4)=="auto") {
+      //TODO fix const auto
+      if((spelling.size()>=4 && spelling.substr(0, 4)=="auto")) {
         auto_end=spelling.substr(4);
         auto type=clang_getCanonicalType(clang_getCursorType(clang_cursors[c]));
         auto cxstr=clang_getTypeSpelling(type);
@@ -47,7 +44,7 @@ void clang::Tokens::get_token_types(clang::TranslationUnit *tu) {
         if(spelling.find(" ")==std::string::npos)
           spelling+=auto_end;
       }
-      tks[c].type=spelling;
+      (*this)[c].type=spelling;
       //std::cout << clang_getCString(clang_getTypeSpelling(type)) << ": " << type.kind << endl;
       ////auto cursor=clang_getTypeDeclaration(type); 
       ////tks[c].type=clang_getCString(clang_getCursorSpelling(cursor));
diff --git a/src/Tokens.h b/src/Tokens.h
index 2fc3de8..ee3f883 100644
--- a/src/Tokens.h
+++ b/src/Tokens.h
@@ -5,14 +5,12 @@
 #include "Token.h"
 
 namespace clang {
-  class Tokens {
+  class Tokens : public std::vector<clang::Token> {
   public:
     Tokens(TranslationUnit *tu, SourceRange *range);
     ~Tokens();
-    std::vector<Token>& tokens();
-    void get_token_types(clang::TranslationUnit *tu);
+    void update_types(clang::TranslationUnit *tu);
   private:
-    std::vector<clang::Token> tks;
     CXToken *tokens_;
     unsigned num_tokens_;
     TranslationUnit& tu;
diff --git a/src/TranslationUnit.cc b/src/TranslationUnit.cc
index 1587a6c..09a9b67 100644
--- a/src/TranslationUnit.cc
+++ b/src/TranslationUnit.cc
@@ -90,12 +90,11 @@ unsigned clang::TranslationUnit::DefaultFlags() {
   return CXTranslationUnit_CacheCompletionResults | CXTranslationUnit_PrecompiledPreamble | CXTranslationUnit_Incomplete;
 }
 
-std::vector<clang::Diagnostic> clang::TranslationUnit::get_diagnostics() {
-  std::vector<clang::Diagnostic> diagnostics;
+void clang::TranslationUnit::update_diagnostics() {
+  diagnostics.clear();
   for(unsigned c=0;c<clang_getNumDiagnostics(tu_);c++) {
     CXDiagnostic clang_diagnostic=clang_getDiagnostic(tu_, c);
     diagnostics.emplace_back(clang::Diagnostic(*this, clang_diagnostic));
     clang_disposeDiagnostic(clang_diagnostic);
   }
-  return diagnostics;
 }
diff --git a/src/TranslationUnit.h b/src/TranslationUnit.h
index eb63128..038093c 100644
--- a/src/TranslationUnit.h
+++ b/src/TranslationUnit.h
@@ -36,8 +36,9 @@ namespace clang {
                                &buffers,
                                unsigned flags=DefaultFlags());
     static unsigned DefaultFlags();
-    std::vector<clang::Diagnostic> get_diagnostics();
+    void update_diagnostics();
     
+    std::vector<clang::Diagnostic> diagnostics;
   private:
     friend Token;
     friend Tokens;
diff --git a/tests/Diagnostics_Test.cc b/tests/Diagnostics_Test.cc
index f9e819d..6351552 100644
--- a/tests/Diagnostics_Test.cc
+++ b/tests/Diagnostics_Test.cc
@@ -20,13 +20,13 @@ BOOST_AUTO_TEST_CASE(diagnostics_test) {
   std::vector<std::string> args;  
   clang::TranslationUnit tu(&index, path, args, map_buffers);
   
-  auto diagnostics=tu.get_diagnostics();
-  BOOST_CHECK(diagnostics.size()==1);
-  BOOST_CHECK(diagnostics[0].spelling=="use of undeclared identifier 'undeclared_variable'");
-  BOOST_CHECK(diagnostics[0].path=="./case/main_error.cpp");
-  BOOST_CHECK(diagnostics[0].severity==3);
-  BOOST_CHECK(diagnostics[0].start_location.line==5);
-  BOOST_CHECK(diagnostics[0].end_location.line==5);
-  BOOST_CHECK(diagnostics[0].start_location.column==16);
-  BOOST_CHECK(diagnostics[0].end_location.column==35);  
+  tu.update_diagnostics();
+  BOOST_CHECK(tu.diagnostics.size()==1);
+  BOOST_CHECK(tu.diagnostics[0].spelling=="use of undeclared identifier 'undeclared_variable'");
+  BOOST_CHECK(tu.diagnostics[0].path=="./case/main_error.cpp");
+  BOOST_CHECK(tu.diagnostics[0].severity==3);
+  BOOST_CHECK(tu.diagnostics[0].start_location.line==5);
+  BOOST_CHECK(tu.diagnostics[0].end_location.line==5);
+  BOOST_CHECK(tu.diagnostics[0].start_location.column==16);
+  BOOST_CHECK(tu.diagnostics[0].end_location.column==35);  
 }
diff --git a/tests/SourceLocation_H_Test.cc b/tests/SourceLocation_H_Test.cc
index 776fcf7..308fe6a 100644
--- a/tests/SourceLocation_H_Test.cc
+++ b/tests/SourceLocation_H_Test.cc
@@ -13,7 +13,7 @@ BOOST_AUTO_TEST_CASE(source_location) {
   clang::SourceRange range(&start, &end);
   clang::Tokens tokens(&tu, &range);
 
-  clang::SourceRange token_range  = tokens.tokens()[28].get_source_range(&tu);
+  clang::SourceRange token_range  = tokens[28].get_source_range(&tu);
 
   unsigned token_start_line, token_start_column, token_start_offset,
     token_end_line, token_end_column, token_end_offset;
diff --git a/tests/Token_H_Test.cc b/tests/Token_H_Test.cc
index 0b166e2..8befb20 100644
--- a/tests/Token_H_Test.cc
+++ b/tests/Token_H_Test.cc
@@ -15,9 +15,9 @@ BOOST_AUTO_TEST_CASE(token) {
 
   clang::Tokens tokens(&tu, &range);
 
-  BOOST_CHECK(tokens.tokens().size() == 32);
-  BOOST_CHECK(tokens.tokens()[1].kind() == clang::TokenKind::Token_Identifier);
+  BOOST_CHECK(tokens.size() == 32);
+  BOOST_CHECK(tokens[1].kind() == clang::TokenKind::Token_Identifier);
 
-  std::string str = tokens.tokens()[28].get_token_spelling(&tu);
+  std::string str = tokens[28].get_token_spelling(&tu);
   BOOST_CHECK(str == "return");  
 }