examples: Cleanup C++ examples

Modify the C++ examples to be of same coding standard like C. As a
part of this cleanup, a new LED example is also added.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>

examples/c++/gpio_advanced.cpp

@@ -0,0 +1,73 @@
+/*
+ * Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
+ * Copyright (c) 2018 Linaro Ltd.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Example usage: Configures GPIO pin for interrupt and waits 30 seconds for the isr to trigger
+ *
+ */
+
+/* standard headers */
+#include <iostream>
+#include <stdlib.h>
+#include <unistd.h>
+
+/* mraa headers */
+#include "mraa/common.hpp"
+#include "mraa/gpio.hpp"
+
+#define GPIO_PIN 6
+
+void
+int_handler(void* args)
+{
+    std::cout << "ISR triggered" << std::endl;
+}
+
+int
+main(void)
+{
+    mraa::Result status;
+
+    //! [Interesting]
+    /* initialize GPIO */
+    mraa::Gpio gpio(GPIO_PIN);
+
+    /* set GPIO to input */
+    status = gpio.dir(mraa::DIR_IN);
+    if (status != mraa::SUCCESS) {
+        printError(status);
+        return EXIT_FAILURE;
+    }
+
+    /* configure ISR for GPIO */
+    status = gpio.isr(mraa::EDGE_BOTH, &int_handler, NULL);
+    if (status != mraa::SUCCESS) {
+        printError(status);
+        return EXIT_FAILURE;
+    }
+
+    /* wait 30 seconds isr trigger */
+    sleep(30);
+    //! [Interesting]
+
+    return EXIT_SUCCESS;
+}