avoid unnecessary empty strings ("") in favor of clear() and empty() (performance)

examples/associative_storage/associative_storage.cpp

@@ -30,7 +30,7 @@ public:
         connection_data data;
 
         data.sessionid = m_next_sessionid++;
-        data.name = "";
+        data.name.clear();
 
         m_connections[hdl] = data;
     }
@@ -47,7 +47,7 @@ public:
     void on_message(connection_hdl hdl, server::message_ptr msg) {
         connection_data& data = get_data_from_hdl(hdl);
 
-        if (data.name == "") {
+        if (data.name.empty()) {
             data.name = msg->get_payload();
             std::cout << "Setting name of connection with sessionid "
                       << data.sessionid << " to " << data.name << std::endl;

examples/enriched_storage/enriched_storage.cpp

@@ -61,7 +61,7 @@ public:
     void on_message(connection_hdl hdl, server::message_ptr msg) {
         connection_ptr con = m_server.get_con_from_hdl(hdl);
         
-        if (con->name == "") {
+        if (con->name.empty()) {
             con->name = msg->get_payload();
             std::cout << "Setting name of connection with sessionid " 
                       << con->sessionid << " to " << con->name << std::endl;

examples/scratch_client/scratch_client.cpp

@@ -246,7 +246,7 @@ int main() {
             std::string cmd;
             int id;
             int close_code = websocketpp::close::status::normal;
-            std::string reason = "";
+            std::string reason;
             
             ss >> cmd >> id >> close_code;
             std::getline(ss,reason);

examples/utility_client/utility_client.cpp

@@ -289,7 +289,7 @@ int main() {
             
             std::string cmd;
             int id;
-            std::string message = "";
+            std::string message;
             
             ss >> cmd >> id;
             std::getline(ss,message);
@@ -301,7 +301,7 @@ int main() {
             std::string cmd;
             int id;
             int close_code = websocketpp::close::status::normal;
-            std::string reason = "";
+            std::string reason;
             
             ss >> cmd >> id >> close_code;
             std::getline(ss,reason);

test/extension/permessage_deflate.cpp

@@ -113,7 +113,7 @@ BOOST_AUTO_TEST_CASE( negotiate_server_no_context_takeover_invalid ) {
 
 BOOST_AUTO_TEST_CASE( negotiate_server_no_context_takeover ) {
     ext_vars v;
-    v.attr["server_no_context_takeover"] = "";
+    v.attr["server_no_context_takeover"].clear();
 
     v.esp = v.exts.negotiate(v.attr);
     BOOST_CHECK( v.exts.is_enabled() );
@@ -144,7 +144,7 @@ BOOST_AUTO_TEST_CASE( negotiate_client_no_context_takeover_invalid ) {
 
 BOOST_AUTO_TEST_CASE( negotiate_client_no_context_takeover ) {
     ext_vars v;
-    v.attr["client_no_context_takeover"] = "";
+    v.attr["client_no_context_takeover"].clear();
 
     v.esp = v.exts.negotiate(v.attr);
     BOOST_CHECK( v.exts.is_enabled() );
@@ -282,7 +282,7 @@ BOOST_AUTO_TEST_CASE( negotiate_client_max_window_bits_invalid ) {
 BOOST_AUTO_TEST_CASE( negotiate_client_max_window_bits_valid ) {
     ext_vars v;
 
-    v.attr["client_max_window_bits"] = "";
+    v.attr["client_max_window_bits"].clear();
     v.esp = v.exts.negotiate(v.attr);
     BOOST_CHECK( v.exts.is_enabled() );
     BOOST_CHECK_EQUAL( v.esp.first, websocketpp::lib::error_code() );
@@ -364,8 +364,8 @@ BOOST_AUTO_TEST_CASE( negotiate_client_max_window_bits_smallest ) {
 BOOST_AUTO_TEST_CASE( negotiate_two_client_initiated1 ) {
     ext_vars v;
 
-    v.attr["server_no_context_takeover"] = "";
-    v.attr["client_no_context_takeover"] = "";
+    v.attr["server_no_context_takeover"].clear();
+    v.attr["client_no_context_takeover"].clear();
 
     v.esp = v.exts.negotiate(v.attr);
     BOOST_CHECK( v.exts.is_enabled() );
@@ -376,7 +376,7 @@ BOOST_AUTO_TEST_CASE( negotiate_two_client_initiated1 ) {
 BOOST_AUTO_TEST_CASE( negotiate_two_client_initiated2 ) {
     ext_vars v;
 
-    v.attr["server_no_context_takeover"] = "";
+    v.attr["server_no_context_takeover"].clear();
     v.attr["server_max_window_bits"] = "10";
 
     v.esp = v.exts.negotiate(v.attr);
@@ -388,7 +388,7 @@ BOOST_AUTO_TEST_CASE( negotiate_two_client_initiated2 ) {
 BOOST_AUTO_TEST_CASE( negotiate_two_client_initiated3 ) {
     ext_vars v;
 
-    v.attr["server_no_context_takeover"] = "";
+    v.attr["server_no_context_takeover"].clear();
     v.attr["client_max_window_bits"] = "10";
 
     v.esp = v.exts.negotiate(v.attr);
@@ -400,7 +400,7 @@ BOOST_AUTO_TEST_CASE( negotiate_two_client_initiated3 ) {
 BOOST_AUTO_TEST_CASE( negotiate_two_client_initiated4 ) {
     ext_vars v;
 
-    v.attr["client_no_context_takeover"] = "";
+    v.attr["client_no_context_takeover"].clear();
     v.attr["server_max_window_bits"] = "10";
 
     v.esp = v.exts.negotiate(v.attr);
@@ -412,7 +412,7 @@ BOOST_AUTO_TEST_CASE( negotiate_two_client_initiated4 ) {
 BOOST_AUTO_TEST_CASE( negotiate_two_client_initiated5 ) {
     ext_vars v;
 
-    v.attr["client_no_context_takeover"] = "";
+    v.attr["client_no_context_takeover"].clear();
     v.attr["client_max_window_bits"] = "10";
 
     v.esp = v.exts.negotiate(v.attr);
@@ -436,8 +436,8 @@ BOOST_AUTO_TEST_CASE( negotiate_two_client_initiated6 ) {
 BOOST_AUTO_TEST_CASE( negotiate_three_client_initiated1 ) {
     ext_vars v;
 
-    v.attr["server_no_context_takeover"] = "";
-    v.attr["client_no_context_takeover"] = "";
+    v.attr["server_no_context_takeover"].clear();
+    v.attr["client_no_context_takeover"].clear();
     v.attr["server_max_window_bits"] = "10";
 
     v.esp = v.exts.negotiate(v.attr);
@@ -449,8 +449,8 @@ BOOST_AUTO_TEST_CASE( negotiate_three_client_initiated1 ) {
 BOOST_AUTO_TEST_CASE( negotiate_three_client_initiated2 ) {
     ext_vars v;
 
-    v.attr["server_no_context_takeover"] = "";
-    v.attr["client_no_context_takeover"] = "";
+    v.attr["server_no_context_takeover"].clear();
+    v.attr["client_no_context_takeover"].clear();
     v.attr["client_max_window_bits"] = "10";
 
     v.esp = v.exts.negotiate(v.attr);
@@ -462,7 +462,7 @@ BOOST_AUTO_TEST_CASE( negotiate_three_client_initiated2 ) {
 BOOST_AUTO_TEST_CASE( negotiate_three_client_initiated3 ) {
     ext_vars v;
 
-    v.attr["server_no_context_takeover"] = "";
+    v.attr["server_no_context_takeover"].clear();
     v.attr["server_max_window_bits"] = "10";
     v.attr["client_max_window_bits"] = "10";
 
@@ -475,7 +475,7 @@ BOOST_AUTO_TEST_CASE( negotiate_three_client_initiated3 ) {
 BOOST_AUTO_TEST_CASE( negotiate_three_client_initiated4 ) {
     ext_vars v;
 
-    v.attr["client_no_context_takeover"] = "";
+    v.attr["client_no_context_takeover"].clear();
     v.attr["server_max_window_bits"] = "10";
     v.attr["client_max_window_bits"] = "10";
 
@@ -488,8 +488,8 @@ BOOST_AUTO_TEST_CASE( negotiate_three_client_initiated4 ) {
 BOOST_AUTO_TEST_CASE( negotiate_four_client_initiated ) {
     ext_vars v;
 
-    v.attr["server_no_context_takeover"] = "";
-    v.attr["client_no_context_takeover"] = "";
+    v.attr["server_no_context_takeover"].clear();
+    v.attr["client_no_context_takeover"].clear();
     v.attr["server_max_window_bits"] = "10";
     v.attr["client_max_window_bits"] = "10";
 
@@ -569,7 +569,7 @@ BOOST_AUTO_TEST_CASE( compress_data_no_context_takeover ) {
 
     websocketpp::http::attribute_list alist;
 
-    alist["server_no_context_takeover"] = "";
+    alist["server_no_context_takeover"].clear();
     v.exts.enable_server_no_context_takeover();
 
     v.exts.negotiate(alist);
@@ -586,7 +586,7 @@ BOOST_AUTO_TEST_CASE( compress_data_no_context_takeover ) {
     BOOST_CHECK_EQUAL( v.ec, websocketpp::lib::error_code() );
     BOOST_CHECK_EQUAL( compress_in, decompress_out );
 
-    decompress_out = "";
+    decompress_out.clear();
 
     v.ec = v.exts.compress(compress_in,compress_out2);
     BOOST_CHECK_EQUAL( v.ec, websocketpp::lib::error_code() );
@@ -605,7 +605,7 @@ BOOST_AUTO_TEST_CASE( compress_data_no_context_takeover ) {
 BOOST_AUTO_TEST_CASE( compress_empty ) {
     ext_vars v;
 
-    std::string compress_in = "";
+    std::string compress_in;
     std::string compress_out;
     std::string decompress_out;
 
@@ -616,8 +616,8 @@ BOOST_AUTO_TEST_CASE( compress_empty ) {
 
     v.ec = v.exts.decompress(reinterpret_cast<const uint8_t *>(compress_out.data()),compress_out.size(),decompress_out);
 
-    compress_out = "";
-    decompress_out = "";
+    compress_out.clear();
+    decompress_out.clear();
 
     v.ec = v.exts.compress(compress_in,compress_out);
     BOOST_CHECK_EQUAL( v.ec, websocketpp::lib::error_code() );
@@ -637,7 +637,7 @@ BOOST_AUTO_TEST_CASE( decompress_data ) {
     ext_vars v;
 
     uint8_t in[11] = {0xf2, 0x48, 0xcd, 0xc9, 0xc9, 0x07, 0x00, 0x00, 0x00, 0xff, 0xff};
-    std::string out = "";
+    std::string out;
     std::string reference = "Hello";
 
     v.exts.init(true);

test/http/parser.cpp

@@ -115,7 +115,7 @@ BOOST_AUTO_TEST_CASE( extract_token ) {
     BOOST_CHECK( ret.second == d1.begin()+3 );
 
     ret = websocketpp::http::parser::extract_token(d2.begin(),d2.end());
-    BOOST_CHECK( ret.first == "" );
+    BOOST_CHECK( ret.first.empty() );
     BOOST_CHECK( ret.second == d2.begin()+0 );
 
     ret = websocketpp::http::parser::extract_token(d2.begin()+1,d2.end());
@@ -127,7 +127,7 @@ BOOST_AUTO_TEST_CASE( extract_quoted_string ) {
     std::string d1 = "\"foo\"";
     std::string d2 = "\"foo\\\"bar\\\"baz\"";
     std::string d3 = "\"foo\"     ";
-    std::string d4 = "";
+    std::string d4;
     std::string d5 = "foo";
 
     std::pair<std::string,std::string::const_iterator> ret;
@@ -147,11 +147,11 @@ BOOST_AUTO_TEST_CASE( extract_quoted_string ) {
     BOOST_CHECK( ret.second == d3.begin()+5 );
 
     ret = extract_quoted_string(d4.begin(),d4.end());
-    BOOST_CHECK( ret.first == "" );
+    BOOST_CHECK( ret.first.empty() );
     BOOST_CHECK( ret.second == d4.begin() );
 
     ret = extract_quoted_string(d5.begin(),d5.end());
-    BOOST_CHECK( ret.first == "" );
+    BOOST_CHECK( ret.first.empty() );
     BOOST_CHECK( ret.second == d5.begin() );
 }
 
@@ -185,7 +185,7 @@ BOOST_AUTO_TEST_CASE( extract_all_lws ) {
 }
 
 BOOST_AUTO_TEST_CASE( extract_attributes_blank ) {
-    std::string s = "";
+    std::string s;
 
     websocketpp::http::attribute_list a;
     std::string::const_iterator it;
@@ -209,7 +209,7 @@ BOOST_AUTO_TEST_CASE( extract_attributes_simple ) {
 }
 
 BOOST_AUTO_TEST_CASE( extract_parameters ) {
-    std::string s1 = "";
+    std::string s1;
     std::string s2 = "foo";
     std::string s3 = " foo \r\nAbc";
     std::string s4 = "  \r\n   foo  ";
@@ -410,7 +410,7 @@ BOOST_AUTO_TEST_CASE( case_insensitive_headers_overwrite ) {
 BOOST_AUTO_TEST_CASE( blank_consume ) {
     websocketpp::http::parser::request r;
 
-    std::string raw = "";
+    std::string raw;
 
     bool exception = false;
 

test/processors/extension_permessage_compress.cpp

@@ -165,7 +165,7 @@ BOOST_AUTO_TEST_CASE( deflate_init ) {
               << websocketpp::utility::to_hex(test_out,test_out_size) << std::endl;
 
     std::string input = "Hello";
-    std::string output = "";
+    std::string output;
     ec = de.compress(input,output);
 
     BOOST_CHECK( ec == processor::extensions::error::uninitialized );
@@ -181,7 +181,7 @@ BOOST_AUTO_TEST_CASE( deflate_init ) {
               << websocketpp::utility::to_hex(input) << std::endl
               << websocketpp::utility::to_hex(output) << std::endl;
 
-    output = "";
+    output.clear();
 
     ec = de.compress(input,output);
     std::cout << ec.message() << std::endl
@@ -189,7 +189,7 @@ BOOST_AUTO_TEST_CASE( deflate_init ) {
               << websocketpp::utility::to_hex(output) << std::endl;
 
     input = output;
-    output = "";
+    output.clear();
     ec = de.decompress(input,output);
     std::cout << ec.message() << std::endl
               << websocketpp::utility::to_hex(input) << std::endl

test/roles/server.cpp

@@ -103,7 +103,7 @@ bool validate_func_subprotocol(server* s, std::string* out, std::string accept,
 
     *out = o.str();
 
-    if (accept != "") {
+    if (!accept.empty()) {
         con->select_subprotocol(accept);
     }
 

test/utility/close.cpp

@@ -88,7 +88,7 @@ BOOST_AUTO_TEST_CASE( value_extraction ) {
 
 BOOST_AUTO_TEST_CASE( extract_empty ) {
     lib::error_code ec;
-    std::string payload = "";
+    std::string payload;
 
     BOOST_CHECK( close::extract_code(payload,ec) == close::status::no_status );
     BOOST_CHECK( !ec );
@@ -109,12 +109,12 @@ BOOST_AUTO_TEST_CASE( extract_reason ) {
     BOOST_CHECK( close::extract_reason(payload,ec) == "Foo" );
     BOOST_CHECK( !ec );
 
-    payload = "";
-    BOOST_CHECK( close::extract_reason(payload,ec) == "" );
+    payload.clear();
+    BOOST_CHECK( close::extract_reason(payload,ec).empty() );
     BOOST_CHECK( !ec );
 
     payload = "00";
-    BOOST_CHECK( close::extract_reason(payload,ec) == "" );
+    BOOST_CHECK( close::extract_reason(payload,ec).empty() );
     BOOST_CHECK( !ec );
 
     payload = "000";

tutorials/utility_client/step5.cpp

@@ -246,7 +246,7 @@ int main() {
             std::string cmd;
             int id;
             int close_code = websocketpp::close::status::normal;
-            std::string reason = "";
+            std::string reason;
             
             ss >> cmd >> id >> close_code;
             std::getline(ss,reason);

tutorials/utility_client/step6.cpp

@@ -289,7 +289,7 @@ int main() {
             
             std::string cmd;
             int id;
-            std::string message = "";
+            std::string message;
             
             ss >> cmd >> id;
             std::getline(ss,message);
@@ -301,7 +301,7 @@ int main() {
             std::string cmd;
             int id;
             int close_code = websocketpp::close::status::normal;
-            std::string reason = "";
+            std::string reason;
             
             ss >> cmd >> id >> close_code;
             std::getline(ss,reason);

tutorials/utility_client/utility_client.md

@@ -602,7 +602,7 @@ else if (input.substr(0,5) == "close") {
     std::string cmd;
     int id;
     int close_code = websocketpp::close::status::normal;
-    std::string reason = "";
+    std::string reason;
     
     ss >> cmd >> id >> close_code;
     std::getline(ss,reason);

websocketpp/close.hpp

@@ -322,7 +322,7 @@ inline status::value extract_code(std::string const & payload, lib::error_code
 inline std::string extract_reason(std::string const & payload, lib::error_code
     & ec)
 {
-    std::string reason = "";
+    std::string reason;
     ec = lib::error_code();
 
     if (payload.size() > 2) {

websocketpp/connection.hpp

@@ -1385,7 +1385,7 @@ private:
      * @return A status code, zero on success, non-zero otherwise
      */
     lib::error_code send_close_ack(close::status::value code =
-        close::status::blank, std::string const & reason = "");
+        close::status::blank, std::string const & reason = std::string());
 
     /// Send close frame
     /**
@@ -1403,7 +1403,7 @@ private:
      * @return A status code, zero on success, non-zero otherwise
      */
     lib::error_code send_close_frame(close::status::value code =
-        close::status::blank, std::string const & reason = "", bool ack = false,
+        close::status::blank, std::string const & reason = std::string(), bool ack = false,
         bool terminal = false);
 
     /// Get a pointer to a new WebSocket protocol processor for a given version

websocketpp/http/constants.hpp

@@ -59,7 +59,7 @@ namespace http {
     static char const header_separator[] = ":";
 
     /// Literal value of an empty header
-    static std::string const empty_header = "";
+    static std::string const empty_header;
 
     /// Maximum size in bytes before rejecting an HTTP header as too big.
     size_t const max_header_size = 16000;
@@ -284,8 +284,8 @@ namespace http {
     public:
         exception(const std::string& log_msg,
                   status_code::value error_code,
-                  const std::string& error_msg = "",
-                  const std::string& body = "")
+                  const std::string& error_msg = std::string(),
+                  const std::string& body = std::string())
           : m_msg(log_msg)
           , m_error_msg(error_msg)
           , m_body(body)

websocketpp/http/impl/parser.hpp

@@ -71,7 +71,7 @@ inline void parser::append_header(std::string const & key, std::string const &
         throw exception("Invalid header name",status_code::bad_request);
     }
 
-    if (this->get_header(key) == "") {
+    if (this->get_header(key).empty()) {
         m_headers[key] = val;
     } else {
         m_headers[key] += ", " + val;
@@ -91,7 +91,7 @@ inline void parser::remove_header(std::string const & key) {
 inline void parser::set_body(std::string const & value) {
     if (value.size() == 0) {
         remove_header("Content-Length");
-        m_body = "";
+        m_body.clear();
         return;
     }
 
@@ -117,7 +117,7 @@ inline bool parser::parse_parameter_list(std::string const & in,
 }
 
 inline bool parser::prepare_body() {
-    if (get_header("Content-Length") != "") {
+    if (!get_header("Content-Length").empty()) {
         std::string const & cl_header = get_header("Content-Length");
         char * end;
         

websocketpp/http/impl/request.hpp

@@ -88,7 +88,7 @@ inline size_t request::consume(char const * buf, size_t len) {
         //the range [begin,end) now represents a line to be processed.
         if (end-begin == 0) {
             // we got a blank line
-            if (m_method.empty() || get_header("Host") == "") {
+            if (m_method.empty() || get_header("Host").empty()) {
                 throw exception("Incomplete Request",status_code::bad_request);
             }
 

websocketpp/http/impl/response.hpp

@@ -94,7 +94,7 @@ inline size_t response::consume(char const * buf, size_t len) {
             // TODO: grab content-length
             std::string length = get_header("Content-Length");
 
-            if (length == "") {
+            if (length.empty()) {
                 // no content length found, read indefinitely
                 m_read = 0;
             } else {

websocketpp/http/parser.hpp

@@ -230,7 +230,7 @@ InputIterator extract_attributes(InputIterator begin, InputIterator end,
         cursor = http::parser::extract_all_lws(cursor,end);
         ret = http::parser::extract_token(cursor,end);
 
-        if (ret.first == "") {
+        if (ret.first.empty()) {
             // error: expected a token
             return begin;
         } else {
@@ -242,7 +242,7 @@ InputIterator extract_attributes(InputIterator begin, InputIterator end,
         if (cursor == end || *cursor != '=') {
             // if there is an equals sign, read the attribute value. Otherwise
             // record a blank value and continue
-            attributes[name] = "";
+            attributes[name].clear();
             continue;
         }
 
@@ -263,7 +263,7 @@ InputIterator extract_attributes(InputIterator begin, InputIterator end,
         }
 
         ret = http::parser::extract_token(cursor,end);
-        if (ret.first == "") {
+        if (ret.first.empty()) {
             // error : expected token or quoted string
             return begin;
         } else {
@@ -321,7 +321,7 @@ InputIterator extract_parameters(InputIterator begin, InputIterator end,
 
         ret = http::parser::extract_token(cursor,end);
 
-        if (ret.first == "") {
+        if (ret.first.empty()) {
             // error: expected a token
             return begin;
         } else {

websocketpp/impl/connection_impl.hpp

@@ -900,7 +900,7 @@ void connection<config>::handle_read_handshake(lib::error_code const & ec,
 
         if (m_alog.static_test(log::alevel::devel)) {
             m_alog.write(log::alevel::devel,m_request.raw());
-            if (m_request.get_header("Sec-WebSocket-Key3") != "") {
+            if (!m_request.get_header("Sec-WebSocket-Key3").empty()) {
                 m_alog.write(log::alevel::devel,
                     utility::to_hex(m_request.get_header("Sec-WebSocket-Key3")));
             }
@@ -1160,7 +1160,7 @@ lib::error_code connection<config>::initialize_processor() {
     m_response.set_status(http::status_code::bad_request);
 
     std::stringstream ss;
-    std::string sep = "";
+    std::string sep;
     std::vector<int>::const_iterator it;
     for (it = versions_supported.begin(); it != versions_supported.end(); it++)
     {
@@ -1308,7 +1308,7 @@ void connection<config>::write_http_response(lib::error_code const & ec) {
     m_response.set_version("HTTP/1.1");
 
     // Set server header based on the user agent settings
-    if (m_response.get_header("Server") == "") {
+    if (m_response.get_header("Server").empty()) {
         if (!m_user_agent.empty()) {
             m_response.replace_header("Server",m_user_agent);
         } else {
@@ -1326,7 +1326,7 @@ void connection<config>::write_http_response(lib::error_code const & ec) {
 
     if (m_alog.static_test(log::alevel::devel)) {
         m_alog.write(log::alevel::devel,"Raw Handshake response:\n"+m_handshake_buffer);
-        if (m_response.get_header("Sec-WebSocket-Key3") != "") {
+        if (!m_response.get_header("Sec-WebSocket-Key3").empty()) {
             m_alog.write(log::alevel::devel,
                 utility::to_hex(m_response.get_header("Sec-WebSocket-Key3")));
         }
@@ -1450,7 +1450,7 @@ void connection<config>::send_http_request() {
     }
 
     // Unless the user has overridden the user agent, send generic WS++ UA.
-    if (m_request.get_header("User-Agent") == "") {
+    if (m_request.get_header("User-Agent").empty()) {
         if (!m_user_agent.empty()) {
             m_request.replace_header("User-Agent",m_user_agent);
         } else {
@@ -2075,7 +2075,7 @@ lib::error_code connection<config>::send_close_frame(close::status::value code,
     if (config::silent_close) {
         m_alog.write(log::alevel::devel,"closing silently");
         m_local_close_code = close::status::no_status;
-        m_local_close_reason = "";
+        m_local_close_reason.clear();
     } else if (code != close::status::blank) {
         m_alog.write(log::alevel::devel,"closing with specified codes");
         m_local_close_code = code;
@@ -2083,12 +2083,12 @@ lib::error_code connection<config>::send_close_frame(close::status::value code,
     } else if (!ack) {
         m_alog.write(log::alevel::devel,"closing with no status code");
         m_local_close_code = close::status::no_status;
-        m_local_close_reason = "";
+        m_local_close_reason.clear();
     } else if (m_remote_close_code == close::status::no_status) {
         m_alog.write(log::alevel::devel,
             "acknowledging a no-status close with normal code");
         m_local_close_code = close::status::normal;
-        m_local_close_reason = "";
+        m_local_close_reason.clear();
     } else {
         m_alog.write(log::alevel::devel,"acknowledging with remote codes");
         m_local_close_code = m_remote_close_code;
@@ -2269,7 +2269,7 @@ void connection<config>::log_open_result()
 
     // User Agent
     std::string ua = m_request.get_header("User-Agent");
-    if (ua == "") {
+    if (ua.empty()) {
         s << "\"\" ";
     } else {
         // check if there are any quotes in the user agent
@@ -2292,9 +2292,9 @@ void connection<config>::log_close_result()
 
     s << "Disconnect "
       << "close local:[" << m_local_close_code
-      << (m_local_close_reason == "" ? "" : ","+m_local_close_reason)
+      << (m_local_close_reason.empty() ? "" : ","+m_local_close_reason)
       << "] remote:[" << m_remote_close_code
-      << (m_remote_close_reason == "" ? "" : ","+m_remote_close_reason) << "]";
+      << (m_remote_close_reason.empty() ? "" : ","+m_remote_close_reason) << "]";
 
     m_alog.write(log::alevel::disconnect,s.str());
 }
@@ -2319,7 +2319,7 @@ void connection<config>::log_fail_result()
 
     // User Agent
     std::string ua = m_request.get_header("User-Agent");
-    if (ua == "") {
+    if (ua.empty()) {
         s << " \"\" ";
     } else {
         // check if there are any quotes in the user agent
@@ -2348,7 +2348,7 @@ void connection<config>::log_http_result() {
     }  
 
     // Connection Type
-    s << (m_request.get_header("host") == "" ? "-" : m_request.get_header("host"))
+    s << (m_request.get_header("host").empty() ? "-" : m_request.get_header("host"))
       << " " << transport_con_type::get_remote_endpoint()
       << " \"" << m_request.get_method() 
       << " " << (m_uri ? m_uri->get_resource() : "-") 
@@ -2357,7 +2357,7 @@ void connection<config>::log_http_result() {
     
     // User Agent
     std::string ua = m_request.get_header("User-Agent");
-    if (ua == "") {
+    if (ua.empty()) {
         s << " \"\" ";
     } else {
         // check if there are any quotes in the user agent

websocketpp/processors/hybi00.hpp

@@ -85,9 +85,9 @@ public:
         // Host is required by HTTP/1.1
         // Connection is required by is_websocket_handshake
         // Upgrade is required by is_websocket_handshake
-        if (r.get_header("Sec-WebSocket-Key1") == "" ||
-            r.get_header("Sec-WebSocket-Key2") == "" ||
-            r.get_header("Sec-WebSocket-Key3") == "")
+        if (r.get_header("Sec-WebSocket-Key1").empty() ||
+            r.get_header("Sec-WebSocket-Key2").empty() ||
+            r.get_header("Sec-WebSocket-Key3").empty())
         {
             return make_error_code(error::missing_required_header);
         }
@@ -126,18 +126,18 @@ public:
 
         // Echo back client's origin unless our local application set a
         // more restrictive one.
-        if (res.get_header("Sec-WebSocket-Origin") == "") {
+        if (res.get_header("Sec-WebSocket-Origin").empty()) {
             res.append_header("Sec-WebSocket-Origin",req.get_header("Origin"));
         }
 
         // Echo back the client's request host unless our local application
         // set a different one.
-        if (res.get_header("Sec-WebSocket-Location") == "") {
+        if (res.get_header("Sec-WebSocket-Location").empty()) {
             uri_ptr uri = get_uri(req);
             res.append_header("Sec-WebSocket-Location",uri->str());
         }
 
-        if (subprotocol != "") {
+        if (!subprotocol.empty()) {
             res.replace_header("Sec-WebSocket-Protocol",subprotocol);
         }
 
@@ -400,7 +400,7 @@ public:
 private:
     void decode_client_key(std::string const & key, char * result) const {
         unsigned int spaces = 0;
-        std::string digits = "";
+        std::string digits;
         uint32_t num;
 
         // key2

websocketpp/processors/hybi13.hpp

@@ -173,7 +173,7 @@ public:
         // Host is required by HTTP/1.1
         // Connection is required by is_websocket_handshake
         // Upgrade is required by is_websocket_handshake
-        if (r.get_header("Sec-WebSocket-Key") == "") {
+        if (r.get_header("Sec-WebSocket-Key").empty()) {
             return make_error_code(error::missing_required_header);
         }
 

websocketpp/processors/processor.hpp

@@ -109,7 +109,7 @@ int get_websocket_version(request_type& r) {
         return -2;
     }
     
-    if (r.get_header("Sec-WebSocket-Version") == "") {
+    if (r.get_header("Sec-WebSocket-Version").empty()) {
         return 0;
     }
 

websocketpp/uri.hpp

@@ -135,7 +135,7 @@ public:
         }
 
         // parse port
-        std::string port = "";
+        std::string port;
         while (state == 1) {
             if (it == uri_string.end()) {
                 // state is not used after this point presently.
@@ -169,7 +169,7 @@ public:
         std::string const & resource)
       : m_scheme(secure ? "wss" : "ws")
       , m_host(host)
-      , m_resource(resource == "" ? "/" : resource)
+      , m_resource(resource.empty() ? "/" : resource)
       , m_port(port)
       , m_secure(secure)
       , m_valid(true) {}
@@ -177,7 +177,7 @@ public:
     uri(bool secure, std::string const & host, std::string const & resource)
       : m_scheme(secure ? "wss" : "ws")
       , m_host(host)
-      , m_resource(resource == "" ? "/" : resource)
+      , m_resource(resource.empty() ? "/" : resource)
       , m_port(secure ? uri_default_secure_port : uri_default_port)
       , m_secure(secure)
       , m_valid(true) {}
@@ -186,7 +186,7 @@ public:
         std::string const & resource)
       : m_scheme(secure ? "wss" : "ws")
       , m_host(host)
-      , m_resource(resource == "" ? "/" : resource)
+      , m_resource(resource.empty() ? "/" : resource)
       , m_secure(secure)
     {
         lib::error_code ec;
@@ -198,7 +198,7 @@ public:
         std::string const & resource)
       : m_scheme(scheme)
       , m_host(host)
-      , m_resource(resource == "" ? "/" : resource)
+      , m_resource(resource.empty() ? "/" : resource)
       , m_port(port)
       , m_secure(scheme == "wss" || scheme == "https")
       , m_valid(true) {}
@@ -206,7 +206,7 @@ public:
     uri(std::string scheme, std::string const & host, std::string const & resource)
       : m_scheme(scheme)
       , m_host(host)
-      , m_resource(resource == "" ? "/" : resource)
+      , m_resource(resource.empty() ? "/" : resource)
       , m_port((scheme == "wss" || scheme == "https") ? uri_default_secure_port : uri_default_port)
       , m_secure(scheme == "wss" || scheme == "https")
       , m_valid(true) {}
@@ -215,7 +215,7 @@ public:
         std::string const & port, std::string const & resource)
       : m_scheme(scheme)
       , m_host(host)
-      , m_resource(resource == "" ? "/" : resource)
+      , m_resource(resource.empty() ? "/" : resource)
       , m_secure(scheme == "wss" || scheme == "https")
     {
         lib::error_code ec;
@@ -321,7 +321,7 @@ private:
     {
         ec = lib::error_code();
 
-        if (port == "") {
+        if (port.empty()) {
             return (m_secure ? uri_default_secure_port : uri_default_port);
         }