Replace use of LinkedList<T> with std::list for AsyncWebServerResponse headers

Fraction of commit 8bb1c70 of dumbfixes
branch of 0xFEEDC0DE64 fork of ESPAsyncWebServer.
This uses defaulted copy constructors for AsyncWebHeader from a previous commit.
Step three of removal of homebrewed LinkedList in favor of standard C++
containers. Also removed from DefaultHeaders class.

Author: avillacis

src/ESPAsyncWebServer.h

@@ -380,7 +380,7 @@ typedef enum {
 class AsyncWebServerResponse {
   protected:
     int _code;
-    LinkedList<AsyncWebHeader *> _headers;
+    std::list<AsyncWebHeader> _headers;
     String _contentType;
     size_t _contentLength;
     bool _sendContentLength;
@@ -463,24 +463,24 @@ class AsyncWebServer {
 };
 
 class DefaultHeaders {
-  using headers_t = LinkedList<AsyncWebHeader *>;
+  using headers_t = std::list<AsyncWebHeader>;
   headers_t _headers;
 
-  DefaultHeaders()
-  :_headers(headers_t([](AsyncWebHeader *h){ delete h; }))
-  {}
 public:
-  using ConstIterator = headers_t::ConstIterator;
+  DefaultHeaders() = default;
+
+  using ConstIterator = headers_t::const_iterator;
 
   void addHeader(const String& name, const String& value){
-    _headers.add(new AsyncWebHeader(name, value));
+    _headers.emplace_back(name, value);
   }
 
   ConstIterator begin() const { return _headers.begin(); }
   ConstIterator end() const { return _headers.end(); }
 
   DefaultHeaders(DefaultHeaders const &) = delete;
   DefaultHeaders &operator=(DefaultHeaders const &) = delete;
+
   static DefaultHeaders &Instance() {
     static DefaultHeaders instance;
     return instance;

src/WebResponses.cpp

@@ -88,7 +88,6 @@ const __FlashStringHelper *AsyncWebServerResponse::responseCodeToString(int code
 
 AsyncWebServerResponse::AsyncWebServerResponse()
   : _code(0)
-  , _headers(LinkedList<AsyncWebHeader *>([](AsyncWebHeader *h){ delete h; }))
   , _contentType()
   , _contentLength(0)
   , _sendContentLength(true)
@@ -99,14 +98,12 @@ AsyncWebServerResponse::AsyncWebServerResponse()
   , _writtenLength(0)
   , _state(RESPONSE_SETUP)
 {
-  for(auto header: DefaultHeaders::Instance()) {
-    _headers.add(new AsyncWebHeader(header->name(), header->value()));
+  for(const auto &header: DefaultHeaders::Instance()) {
+    _headers.emplace_back(header);
   }
 }
 
-AsyncWebServerResponse::~AsyncWebServerResponse(){
-  _headers.free();
-}
+AsyncWebServerResponse::~AsyncWebServerResponse() = default;
 
 void AsyncWebServerResponse::setCode(int code){
   if(_state == RESPONSE_SETUP)
@@ -124,7 +121,7 @@ void AsyncWebServerResponse::setContentType(const String& type){
 }
 
 void AsyncWebServerResponse::addHeader(const String& name, const String& value){
-  _headers.add(new AsyncWebHeader(name, value));
+  _headers.emplace_back(name, value);
 }
 
 String AsyncWebServerResponse::_assembleHead(uint8_t version){
@@ -150,10 +147,10 @@ String AsyncWebServerResponse::_assembleHead(uint8_t version){
   }
 
   for(const auto& header: _headers){
-    snprintf_P(buf, bufSize, PSTR("%s: %s\r\n"), header->name().c_str(), header->value().c_str());
+    snprintf_P(buf, bufSize, PSTR("%s: %s\r\n"), header.name().c_str(), header.value().c_str());
     out.concat(buf);
   }
-  _headers.free();
+  _headers.clear();
 
   out.concat(F("\r\n"));
   _headLength = out.length();