Integrating Return Value class in apis

api/Client.h

@@ -31,10 +31,10 @@ class Client : public Stream {
   virtual ErrorCode connect(const char *host, uint16_t port) =0;
   virtual size_t write(uint8_t) =0;
   virtual size_t write(const uint8_t *buf, size_t size) =0;
-  virtual int available() = 0;
-  virtual int read() = 0;
-  virtual int read(uint8_t *buf, size_t size) = 0;
-  virtual int peek() = 0;
+  virtual ReturnValue available() = 0;
+  virtual ReturnValue read() = 0;
+  virtual ReturnValue read(uint8_t *buf, size_t size) = 0;
+  virtual ReturnValue peek() = 0;
   virtual void flush() = 0;
   virtual void stop() = 0;
   virtual uint8_t connected() = 0;

api/HardwareSerial.h

@@ -92,8 +92,8 @@ class HardwareSerial : public Stream
     virtual ErrorCode begin(unsigned long baudrate, uint16_t config) = 0;
     virtual void end() = 0;
     virtual int available(void) = 0;
-    virtual int peek(void) = 0;
-    virtual int read(void) = 0;
+    virtual ReturnValue peek(void) = 0;
+    virtual ReturnValue read(void) = 0;
     virtual void flush(void) = 0;
     virtual size_t write(uint8_t) = 0;
     using Print::write; // pull in write(str) and write(buf, size) from Print

api/Stream.h

@@ -58,9 +58,9 @@ class Stream : public Print
     int peekNextDigit(LookaheadMode lookahead, bool detectDecimal); // returns the next numeric digit in the stream or -1 if timeout
 
   public:
-    virtual int available() = 0;
-    virtual int read() = 0;
-    virtual int peek() = 0;
+    virtual ReturnValue available() = 0;
+    virtual ReturnValue read() = 0;
+    virtual ReturnValue peek() = 0;
 
     Stream() {_timeout=1000;}