Update H5Fget_obj_count/ids to reflect dtype behavior (#3949)

doxygen/aliases

@@ -363,7 +363,7 @@ ALIASES += indexes="<table><tr><td>#H5_INDEX_NAME</td><td>Lexicographic order on
 ALIASES += link_types="<table><tr><td>#H5L_TYPE_HARD</td><td>Hard link</td></tr><tr><td>#H5L_TYPE_SOFT</td><td>Soft link</td></tr><tr><td>#H5L_TYPE_EXTERNAL</td><td>External link</td></tr><tr><td>#H5L_TYPE_ERROR</td><td>Error</td></tr></table>"
 ALIASES += mem_types="<table><tr><td>#H5FD_MEM_DEFAULT</td><td>The default file memory allocation type</td></tr><tr><td>#H5FD_MEM_SUPER</td><td>File memory allocated for Superblock</td></tr><tr><td>#H5FD_MEM_BTREE</td><td>File memory allocated for B-tree</td></tr><tr><td>#H5FD_MEM_DRAW</td><td>File memory allocated for raw data</td></tr><tr><td>#H5FD_MEM_GHEAP</td><td>File memory allocated for Global Heap</td></tr><tr><td>#H5FD_MEM_LHEAP</td><td>File memory allocated for Local Heap</td></tr><tr><td>#H5FD_MEM_OHDR</td><td>File memory allocated for Object Header</td></tr></table>"
 ALIASES += norm_type="<table><tr><td>#H5T_NORM_IMPLIED</td><td>0</td><td>MSB of mantissa is not stored, always 1</td></tr><tr><td>#H5T_NORM_MSBSET</td><td>1</td><td>MSB of mantissa is always 1</td></tr><tr><td>#H5T_NORM_NONE</td><td>2</td><td>Mantissa is not normalized</td></tr></table>"
-ALIASES += obj_types="<table><tr><td>#H5F_OBJ_FILE</td><td>Files only</td></tr><tr><td>#H5F_OBJ_DATASET</td><td>Datasets only</td></tr><tr><td>#H5F_OBJ_GROUP</td><td>Groups only</td></tr><tr><td>#H5F_OBJ_DATATYPE</td><td>Named datatypes only</td></tr><tr><td>#H5F_OBJ_ATTR</td><td>Attributes only</td></tr><tr><td>#H5F_OBJ_ALL</td><td>All of the above</td></tr></tr><tr><td>#H5F_OBJ_LOCAL</td><td>Restrict search to objects opened through current file identifier.</td></tr></table> \attention #H5F_OBJ_LOCAL does not stand alone; it is effective only when used in combination with one or more of the preceding types. For example, #H5F_OBJ_DATASET | #H5F_OBJ_GROUP | #H5F_OBJ_LOCAL would count all datasets and groups opened through the current file identifier."
+ALIASES += obj_types="<table><tr><td>#H5F_OBJ_FILE</td><td>Files only</td></tr><tr><td>#H5F_OBJ_DATASET</td><td>Datasets only</td></tr><tr><td>#H5F_OBJ_GROUP</td><td>Groups only</td></tr><tr><td>#H5F_OBJ_DATATYPE</td><td>Datatypes only. If \p file_id is #H5F_OBJ_ALL, this will count committed and transient datatypes. Otherwise, it will only count committed datatypes. </td></tr><tr><td>#H5F_OBJ_ATTR</td><td>Attributes only</td></tr><tr><td>#H5F_OBJ_ALL</td><td>All of the above</td></tr></tr><tr><td>#H5F_OBJ_LOCAL</td><td>Restrict search to objects opened through current file identifier.</td></tr></table> \attention #H5F_OBJ_LOCAL does not stand alone; it is effective only when used in combination with one or more of the preceding types. For example, #H5F_OBJ_DATASET | #H5F_OBJ_GROUP | #H5F_OBJ_LOCAL would count all datasets and groups opened through the current file identifier."
 ALIASES += orders="<table><tr><td>#H5_ITER_INC</td><td>Increasing order</td></tr><tr><td>#H5_ITER_DEC</td><td>Decreasing order</td></tr><tr><td>#H5_ITER_NATIVE</td><td>Fastest available order</td></tr></table>"
 ALIASES += padding_type="<table><tr><td>#H5T_PAD_ZERO</td><td>0</td><td>Set background to zeros</td></tr><tr><td>#H5T_PAD_ONE</td><td>1</td><td>Set background to ones</td></tr><tr><td>#H5T_PAD_BACKGROUND</td><td>2</td><td>Leave background alone</td></tr></table>"
 ALIASES += scopes="<table><tr><td>#H5F_SCOPE_GLOBAL</td><td>Flushes the entire virtual file</td></tr><tr><td>#H5F_SCOPE_LOCAL</td><td>Flushes only the specified file</td></tr></table>"

src/H5Fpublic.h

@@ -75,7 +75,7 @@
 #define H5F_OBJ_FILE     (0x0001u) /**< File objects */
 #define H5F_OBJ_DATASET  (0x0002u) /**< Dataset objects */
 #define H5F_OBJ_GROUP    (0x0004u) /**< Group objects */
-#define H5F_OBJ_DATATYPE (0x0008u) /**< Named datatype objects */
+#define H5F_OBJ_DATATYPE (0x0008u) /**< Datatype objects */
 #define H5F_OBJ_ATTR     (0x0010u) /**< Attribute objects */
 #define H5F_OBJ_ALL      (H5F_OBJ_FILE | H5F_OBJ_DATASET | H5F_OBJ_GROUP | H5F_OBJ_DATATYPE | H5F_OBJ_ATTR)
 #define H5F_OBJ_LOCAL                                                                                        \
@@ -760,7 +760,8 @@ H5_DLL herr_t H5Fget_fileno(hid_t file_id, unsigned long *fileno);
  *          object identifiers for the file.
  *
  *          To retrieve a count of open identifiers for open objects in all
- *          HDF5 application files that are currently open, pass the value
+ *          HDF5 application files that are currently open, as well as transient
+ *          datatype objects that are not associated with any file, pass the value
  *          #H5F_OBJ_ALL in \p file_id.
  *
  *          The types of objects to be counted are specified in types as