Added constexpr to CRC1

Author: jwellbelove

include/etl/crc1.h

@@ -52,19 +52,19 @@ namespace etl
     };
 
     //*********************************
-    value_type initial() const
+    ETL_CONSTEXPR14 value_type initial() const
     {
       return even_parity;
     }
 
     //*********************************
-    uint8_t add(int parity, uint8_t value) const
+    ETL_CONSTEXPR14 uint8_t add(int parity, uint8_t value) const
     {
       return parity ^ etl::parity(value);
     }
 
     //*********************************
-    uint8_t final(uint8_t parity) const
+    ETL_CONSTEXPR14 uint8_t final(uint8_t parity) const
     {
       return parity;
     }
@@ -83,7 +83,7 @@ namespace etl
     //*************************************************************************
     /// Default constructor.
     //*************************************************************************
-    crc1()
+    ETL_CONSTEXPR14 crc1()
     {
       this->reset();
     }
@@ -94,7 +94,7 @@ namespace etl
     /// \param end   End of the range.
     //*************************************************************************
     template<typename TIterator>
-    crc1(TIterator begin, const TIterator end)
+    ETL_CONSTEXPR14 crc1(TIterator begin, const TIterator end)
     {
       this->reset();
       this->add(begin, end);

include/etl/frame_check_sequence.h

@@ -107,7 +107,8 @@ namespace etl
     //*************************************************************************
     /// Default constructor.
     //*************************************************************************
-    ETL_CONSTEXPR14 frame_check_sequence() : frame_check()
+    ETL_CONSTEXPR14 frame_check_sequence() 
+      : frame_check()
     {
       reset();
     }

test/test_crc1.cpp

@@ -66,6 +66,17 @@ namespace
       CHECK_EQUAL(calculate_parity(data.begin(), data.end()), int(crc));
     }
 
+#if ETL_USING_CPP14
+    //*************************************************************************
+    TEST(test_crc1_constructor_constexpr)
+    {
+      constexpr char data[] = "123456789";
+      constexpr uint8_t crc = etl::crc1(data, data + 9);
+
+      CHECK_EQUAL(calculate_parity(data, data + 9), int(crc));
+    }
+#endif
+
     //*************************************************************************
     TEST(test_crc1_add_values)
     {