Improve doc

doc/Doxyfile

@@ -1505,6 +1505,8 @@ INCLUDE_FILE_PATTERNS  =
 PREDEFINED             = FOUG_LIB_EXPORT= \
                          FOUG_LIBSUPPORT_EXPORT= \
                          FOUG_DATAX_LIBSTL_EXPORT= \
+                         FOUG_C_LINKAGE_BEGIN= \
+                         FOUG_C_LINKAGE_END= \
                          FOUG_HAVE_STDINT_H=1
 
 # If the MACRO_EXPANSION and EXPAND_ONLY_PREDEF tags are set to YES then 

src/datax_stl/stl_format.c

@@ -11,6 +11,16 @@
 
 #define _INTERNAL_FOUG_FIXED_BUFFER_SIZE  512
 
+/*! \brief Returns the format of the STL data in \p stream
+ *
+ *  It will try to read 512 bytes from \p stream into a buffer and then analyses this data to guess
+ *  the format.
+ *
+ *  Parameter \p data_size must provide the total size (in bytes) of the stream data (e.g. file
+ *  size), it is required to guess endianness in case of binary format.
+ *
+ *  Returns FOUG_STL_UNKNOWN_FORMAT in case of error.
+ */
 foug_stl_format_t foug_stl_get_format(foug_stream_t *stream, size_t data_size)
 {
   char fixed_buffer[_INTERNAL_FOUG_FIXED_BUFFER_SIZE];