Only by visiting each view. You could build something dynamically like:

SQL> select 'select count(*) from '||owner||'.'||view_name||';'
  2  from all_views;

'SELECTCOUNT(*)FROM'||OWNER||'.'||VIEW_NAME||';'
----------------------------------------------------------------------------
select count(*) from SYS.ALL_XML_SCHEMAS;
select count(*) from SYS.ALL_XML_SCHEMAS2;
select count(*) from SYS.V_$MAP_LIBRARY;
select count(*) from SYS.V_$MAP_FILE;
select count(*) from SYS.V_$MAP_FILE_EXTENT;
select count(*) from SYS.V_$MAP_ELEMENT;
...
...

with appropriate predicates to limit it to what you are after