Fixing MacOS build and Spin Test (#9)

* Fixing guid.cpp build error on Mac.

Removing constexpr from functions with reinterpret_cast.

* Fixing Spin_SortValidation on MacOS.

MacOS system_clock only has microsecond precision.
This means we need to wait longer in the test for the timer to change.
Some time > 65 milliseconds.

* Fixing typo and cv -> cV casing in comment.

CorrelationVector/include/correlation_vector/spin_parameters.h

@@ -12,14 +12,14 @@ enum class spin_counter_interval
     /**
         The coarse interval drops the 24 least significant bits in
        time_since_epoch resulting in a counter that increments every 1.67
-       seconds.
+       seconds (on system with 10 million ticks = 1 second).
     */
     coarse = 24,
 
     /**
         The fine interval drops the 16 least significant bits in
        time_since_epoch resulting in a counter that increments every 6.5
-       milliseconds.
+       milliseconds (on system with 10 million ticks = 1 second).
     */
     fine = 16
 };

CorrelationVector/src/guid.cpp

@@ -38,13 +38,13 @@ constexpr std::array<unsigned char, 16> convert_to_array(const unsigned char* g)
 }
 
 #ifdef GUID_WINDOWS
-constexpr std::array<unsigned char, 16> convert_to_array(const GUID& g)
+std::array<unsigned char, 16> convert_to_array(const GUID& g)
 {
     return impl::convert_to_array(reinterpret_cast<const unsigned char*>(&g));
 }
 #endif
 #ifdef GUID_LIBUUID
-constexpr std::array<unsigned char, 16> convert_to_array(const uuid_t& g)
+std::array<unsigned char, 16> convert_to_array(const uuid_t& g)
 {
     return impl::convert_to_array(reinterpret_cast<const unsigned char*>(g));
 }

CorrelationVector/tests/CorrelationVectorTests.cpp

@@ -294,8 +294,17 @@ TEST_CASE("Spin_SortValidation")
 
         lastSpinValue = spinValue;
 
+        // MacOS SYSTEM_CLOCK and std::chrono::system_clock have microsecond precision.
+        // Both Windows and Linux have sub-microsecond precision.
+        // This means we need to wait a bit longer (over 65 milliseconds) on MacOS
+        // for the spin operator to change the value of the cV.
+#ifdef __APPLE__
+        // Wait for 70ms
+        std::this_thread::sleep_for(std::chrono::milliseconds(70));
+#else
         // Wait for 10ms.
         std::this_thread::sleep_for(std::chrono::milliseconds(10));
+#endif
     }
 
     // The counter should wrap at most 1 time.