Unused templates: Remove unused template function with variadic arguments

lib/tokenize.cpp

@@ -4852,8 +4852,11 @@ void Tokenizer::simplifyHeaders()
             if (removeUnusedTemplates || (isIncluded && removeUnusedIncludedTemplates)) {
                 if (Token::Match(tok->next(), "template < %name%")) {
                     const Token *tok2 = tok->tokAt(3);
-                    while (Token::Match(tok2, "%name% %name% [,=>]")) {
+                    while (Token::Match(tok2, "%name% %name% [,=>]") || Token::Match(tok2, "typename . . . %name% [,>]")) {
-                        tok2 = tok2->tokAt(2);
+                        if (Token::simpleMatch(tok2, "typename . . ."))
+                            tok2 = tok2->tokAt(5);
+                        else
+                            tok2 = tok2->tokAt(2);
                         if (Token::Match(tok2, "= %name% [,>]"))
                             tok2 = tok2->tokAt(2);
                         if (tok2->str() == ",")
@@ -4870,6 +4873,9 @@ void Tokenizer::simplifyHeaders()
                             endToken = endToken->link()->next();
                         if (endToken && endToken->str() == ";")
                             Token::eraseTokens(tok, endToken);
+                    } else if (Token::Match(tok2, "> %type% %name% (") && Token::simpleMatch(tok2->linkAt(3), ") {") && keep.find(tok2->strAt(2)) == keep.end()) {
+                        const Token *endToken = tok2->linkAt(3)->linkAt(1)->next();
+                        Token::eraseTokens(tok, endToken);
                     }
                 }
             }

test/testtokenize.cpp

@@ -92,6 +92,8 @@ private:
 
         TEST_CASE(longtok);
 
+        TEST_CASE(removeUnusedTemplates);
+
         TEST_CASE(simplifyCasts1);
         TEST_CASE(simplifyCasts2);
         TEST_CASE(simplifyCasts3);
@@ -550,6 +552,18 @@ private:
             return "";
     }
 
+    std::string tokenizeAndStringify(const char code[], const Settings &settings) {
+        errout.str("");
+
+        // tokenize..
+        Tokenizer tokenizer(&settings, this);
+        std::istringstream istr(code);
+        tokenizer.tokenize(istr, "test.cpp");
+        if (!tokenizer.tokens())
+            return "";
+        return tokenizer.tokens()->stringifyList(false, true, false, true, false, 0, 0);
+    }
+
     std::string tokenizeDebugListing(const char code[], bool simplify = false, const char filename[] = "test.cpp") {
         errout.str("");
 
@@ -974,6 +988,16 @@ private:
     }
 
 
+    void removeUnusedTemplates() {
+        Settings s;
+        s.removeUnusedTemplates = true;
+        ASSERT_EQUALS(";",
+                      tokenizeAndStringify("; template <typename... a> uint8_t b(std::tuple<uint8_t> d) {\n"
+                                           "  std::tuple<a...> c{std::move(d)};\n"
+                                           "  return std::get<0>(c);\n"
+                                           "}", s));
+    }
+
 
     // Don’t remove "(int *)"..
     void simplifyCasts1() {