Update C examples

Author: kgryte

lib/node_modules/@stdlib/os/byte-order/README.md

@@ -111,30 +111,36 @@ if ( BYTE_ORDER === 'little-endian' ) {
 Macro for an arbitrary constant indicating little-endian byte order.
 
 ```c
-#if STDLIB_OS_BYTE_ORDER == STDLIB_OS_BYTE_ORDER_LITTLE_ENDIAN
+#if defined(STDLIB_OS_BYTE_ORDER) && STDLIB_OS_BYTE_ORDER == STDLIB_OS_BYTE_ORDER_LITTLE_ENDIAN
 
 // Do something for little-endian...
 
 #endif
 ```
 
+If compiled on an unrecognized/unsupported platform, the macro is **not** defined.
+
 #### STDLIB_OS_BYTE_ORDER_BIG_ENDIAN
 
 Macro for an arbitrary constant indicating big-endian byte order.
 
 ```c
-#if STDLIB_OS_BYTE_ORDER == STDLIB_OS_BYTE_ORDER_BIG_ENDIAN
+#if defined(STDLIB_OS_BYTE_ORDER) && STDLIB_OS_BYTE_ORDER == STDLIB_OS_BYTE_ORDER_BIG_ENDIAN
 
 // Do something for big-endian...
 
 #endif
 ```
 
+If compiled on an unrecognized/unsupported platform, the macro is **not** defined.
+
 #### STDLIB_OS_BYTE_ORDER
 
 Macro which equals either `STDLIB_OS_BYTE_ORDER_LITTLE_ENDIAN` or `STDLIB_OS_BYTE_ORDER_BIG_ENDIAN` depending on the resolved platform byte order.
 
 ```c
+#if defined(STDLIB_OS_BYTE_ORDER)
+
 #if STDLIB_OS_BYTE_ORDER == STDLIB_OS_BYTE_ORDER_LITTLE_ENDIAN
 
 // Do something for little-endian...
@@ -143,9 +149,13 @@ Macro which equals either `STDLIB_OS_BYTE_ORDER_LITTLE_ENDIAN` or `STDLIB_OS_BYT
 
 // Do something for big-endian...
 
+#endif
+
 #endif
 ```
 
+If compiled on an unrecognized/unsupported platform, the macro is **not** defined.
+
 </section>
 
 <!-- /.usage -->
@@ -169,13 +179,15 @@ Macro which equals either `STDLIB_OS_BYTE_ORDER_LITTLE_ENDIAN` or `STDLIB_OS_BYT
 #include <stdio.h>
 
 int main() {
+#if defined(STDLIB_OS_BYTE_ORDER)
 #if STDLIB_OS_BYTE_ORDER == STDLIB_OS_BYTE_ORDER_LITTLE_ENDIAN
     printf( "Platform is little-endian...\n" );
 #elif STDLIB_OS_BYTE_ORDER == STDLIB_OS_BYTE_ORDER_BIG_ENDIAN
     printf( "Platform is big-endian...\n" );
 #else
     printf( "Platform endianness is either mixed-endian or unknown...\n" )
 #endif
+#endif
 }
 ```
 

lib/node_modules/@stdlib/os/byte-order/examples/c/example.c

@@ -20,11 +20,13 @@
 #include <stdio.h>
 
 int main() {
+#if defined(STDLIB_OS_BYTE_ORDER)
 #if STDLIB_OS_BYTE_ORDER == STDLIB_OS_BYTE_ORDER_LITTLE_ENDIAN
 	printf( "Platform is little-endian...\n" );
 #elif STDLIB_OS_BYTE_ORDER == STDLIB_OS_BYTE_ORDER_BIG_ENDIAN
 	printf( "Platform is big-endian...\n" );
 #else
 	printf( "Platform endianness is either mixed-endian or unknown...\n" )
 #endif
+#endif
 }