moved the byte order function to an implementation file - the constexpr approach does not work on all compliers -- needs > c++11

Author: gigapod

src/sfeTk/sfeToolkit.cpp

@@ -0,0 +1,35 @@
+// File: sfeToolkit.cpp
+//
+// General impl file for the SparkFun Toolkit
+/*
+
+The MIT License (MIT)
+
+Copyright (c) 2024 SparkFun Electronics
+
+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.
+*/
+#include "sfeToolkit.h"
+#include <stdint.h>
+
+/**
+ * @brief C function - Runtime check for system byte order
+ */
+sfeTKByteOrder_t systemByteOrder(void)
+{
+    uint16_t i = 1;
+    return *((uint8_t *)&i) == 0 ? SFETK_BIG_ENDIAN : SFETK_LITTLE_ENDIAN;
+}

src/sfeTk/sfeToolkit.h

@@ -6,7 +6,7 @@
 
 The MIT License (MIT)
 
-Copyright (c) 2023 SparkFun Electronics
+Copyright (c) 2024 SparkFun Electronics
 
 Permission is hereby granted, free of charge, to any person obtaining a
 copy of this software and associated documentation files (the "Software"),
@@ -40,9 +40,13 @@ typedef enum
     SFETK_LITTLE_ENDIAN = 0x00
 } sfeTKByteOrder_t;
 
-// Runtime check for system byte order
-constexpr sfeTKByteOrder_t systemByteOrder(void)
+// Export our byte order function as a C function
+#ifdef __cplusplus
+extern "C"
 {
-    uint16_t i = 1;
-    return *((uint8_t *)&i) == 0 ? SFETK_BIG_ENDIAN : SFETK_LITTLE_ENDIAN;
-}
+#endif
+    // Runtime check for system byte order
+    sfeTKByteOrder_t systemByteOrder(void);
+#ifdef __cplusplus
+}
+#endif