Add support for Print::flush() on ESP32 (espressif/arduino-esp32#6084)

Author: bblanchon

CHANGELOG.md

@@ -1,6 +1,11 @@
 StreamUtils - Change log
 ========================
 
+HEAD
+----
+
+* Add support for `Print::flush()` on ESP32
+
 1.6.3 (2022/05/11)
 -----
 

extras/test/cores/esp32/CMakeLists.txt

@@ -19,4 +19,7 @@ target_include_directories(Esp32Core
 target_compile_definitions(Esp32Core
 	PUBLIC
 		ARDUINO_ARCH_ESP32
+		ESP_ARDUINO_VERSION_MAJOR=2
+		ESP_ARDUINO_VERSION_MINOR=0
+		ESP_ARDUINO_VERSION_PATCH=5
 )

extras/test/cores/esp32/Print.h

@@ -13,6 +13,7 @@ struct Print {
   virtual ~Print() {}
   virtual size_t write(const uint8_t *buffer, size_t size) = 0;
   virtual size_t write(uint8_t data) = 0;
+  virtual void flush() {}
 
   virtual int availableForWrite() {
     return 0;

extras/test/cores/esp32/Stream.h

@@ -12,7 +12,6 @@ struct Stream : Print {
   virtual int available() = 0;
   virtual int read() = 0;
   virtual int peek() = 0;
-  virtual void flush() = 0;
 
   virtual size_t readBytes(char *buffer, size_t length) {
     size_t count = 0;

src/StreamUtils/Configuration.hpp

@@ -5,8 +5,10 @@
 #pragma once
 
 #ifndef STREAMUTILS_PRINT_FLUSH_EXISTS
-#if defined(ARDUINO_ARCH_ESP8266) || defined(ARDUINO_ARCH_SAMD) || \
-    defined(ARDUINO_ARCH_AVR)
+#if defined(ARDUINO_ARCH_ESP8266) || defined(ARDUINO_ARCH_SAMD) ||    \
+    defined(ARDUINO_ARCH_AVR) ||                                      \
+    (defined(ARDUINO_ARCH_ESP32) && ESP_ARDUINO_VERSION_MAJOR >= 2 && \
+     ESP_ARDUINO_VERSION_PATCH >= 3)
 #define STREAMUTILS_PRINT_FLUSH_EXISTS 1
 #else
 #define STREAMUTILS_PRINT_FLUSH_EXISTS 0