examples: Remove heap allocation from C++ examples

Cleanup of UPM C++ examples.  Switched from heap allocation to
stack allocation when possible.  This simplifies the samples since it
removes the need for explicit memory management.  A script was used to
identify and replace pointer use.  To simplify the replace script, I
re-formatted the C++ examples using the UPM .clang-format file.
Unfortuantely this changes the look of the UPM C++ examples to a large
degree.  However, examples will now have a standard look/feel and
uniform formatting.

    * Ran clang-format w/provided UPM .clang-format file
    * Removed new's/delete's whenever possible (left those in interface
      examples)
    * Added IIO sensor library implementation of callback void* arg
    * Converted all sleeps to upm defined delays (added header when
      necessary)
    * Scrubbed CXX example includes

Signed-off-by: Noel Eck <noel.eck@intel.com>

examples/c++/ads1x15-ads1115.cxx

@@ -28,11 +28,13 @@
  */
 
 #include <fstream>
+#include <iostream>
 #include <string>
 #include <thread>
-#include <unistd.h>
 
 #include "ads1115.hpp"
+#include "ads1x15.hpp"
+#include "upm_utilities.h"
 
 using namespace std;
 using namespace upm;
@@ -40,16 +42,18 @@ using namespace upm;
 bool running = true; // Controls main read/write loop
 
 // Thread function
-void stop()
+void
+stop()
 {
-    sleep(10);
+    upm_delay(10);
     running = false;
 }
 
-int main()
+int
+main()
 {
     //! [Interesting]
-    long id = 0; // Sample number
+    long id = 0;                        // Sample number
     string fileName = "./ads1115.data"; // Output filename
     ofstream f;
 
@@ -57,26 +61,26 @@ int main()
     // There are two ADS1115 chips on the DFRobot Joule Shield on the same I2C bus
     //     - 0x48 gives access to pins A0 - A3
     //     - 0x49 gives access to pins A4 - A7
-    ADS1115 *ads1115 = new upm::ADS1115(0, 0x48);
+    ADS1115 ads1115(0, 0x48);
 
     // Put the ADC into differential mode for pins A0 and A1,
     // the SM-24 Geophone is connected to these pins
-    ads1115->getSample(ADS1X15::DIFF_0_1);
+    ads1115.getSample(ADS1X15::DIFF_0_1);
 
     // Set the gain based on expected VIN range to -/+ 2.048 V
     // Can be adjusted based on application to as low as -/+ 0.256 V, see API
     // documentation for details
-    ads1115->setGain(ADS1X15::GAIN_TWO);
+    ads1115.setGain(ADS1X15::GAIN_TWO);
 
     // Set the sample rate to 860 samples per second (max) and turn on continuous
     // sampling
-    ads1115->setSPS(ADS1115::SPS_860);
-    ads1115->setContinuous(true);
+    ads1115.setSPS(ADS1115::SPS_860);
+    ads1115.setContinuous(true);
 
     // Enable exceptions from the output stream
     f.exceptions(ofstream::failbit | ofstream::badbit);
     // Open the file
-    try{
+    try {
         f.open(fileName);
 
         // Output formatting
@@ -84,19 +88,18 @@ int main()
         f.precision(7);
 
         // Start the thread that will stop logging after 10 seconds
-        thread timer (stop);
+        thread timer(stop);
 
         // Read sensor data and write it to the output file every ms
-        while(running){
-            f << id++ << " " << ads1115->getLastSample() << endl;
-            usleep(1000);
+        while (running) {
+            f << id++ << " " << ads1115.getLastSample() << endl;
+            upm_delay_us(1000);
         }
 
         // Clean-up and exit
         timer.join();
         f.close();
-        delete ads1115;
-    } catch (ios_base::failure &e) {
+    } catch (ios_base::failure& e) {
         cout << "Failed to write to file: " << e.what() << endl;
         return 1;
     }
@@ -104,4 +107,3 @@ int main()
     //! [Interesting]
     return 0;
 }
-