@param[in] trace_class Trace class of which to get the packet
header field type.
@returns Packet header field type of \p trace_class,
- or \c NULL on error.
+ or \c NULL if \p trace_class has no packet header field
+ type or on error.
@prenotnull{trace_class}
@postrefcountsame{trace_class}
-@postsuccessrefcountretinc
+@post <strong>On success, if the return value is a field type</strong>, its
+ reference count is incremented.
@sa bt_ctf_trace_set_packet_header_type(): Sets the packet
header field type of a given trace class.
/**
@brief Sets the packet header field type of the CTF IR trace class
- \p trace_class to \p packet_context_type.
+ \p trace_class to \p packet_header_type, or unsets the current packet
+ header field type from \p trace_class.
+
+If \p packet_header_type is \c NULL, then this function unsets the current
+packet header field type from \p trace_class, effectively making \p trace_class
+a trace without a packet header field type.
-As of Babeltrace \btversion, \p packet_context_type \em must be a
-CTF IR structure field type object.
+As of Babeltrace \btversion, if \p packet_header_type is not \c NULL,
+\p packet_header_type \em must be a CTF IR structure field type object.
@param[in] trace_class Trace class of which to set the packet
header field type.
-@param[in] packet_header_type Packet header field type.
+@param[in] packet_header_type Packet header field type, or \c NULL to unset
+ the current packet header field type.
@returns 0 on success, or a negative value on error.
@prenotnull{trace_class}
-@prenotnull{packet_header_type}
@prehot{trace_class}
-@preisstructft{packet_header_type}
+@pre <strong>\p packet_header_type, if not \c NULL</strong>, is a CTF IR
+ structure field type.
@postrefcountsame{trace_class}
-@postsuccessrefcountinc{packet_header_type}
+@post <strong>On success, if \p packet_header_type is not \c NULL</strong>,
+ the reference count of \p packet_header_type is incremented.
@sa bt_ctf_trace_get_packet_header_type(): Returns the packet
header field type of a given trace class.