Additional also rotate_extrude() is available.

Defaults:

• startAngle : 0
• angle: PI * 2
• overflow: 'cap' (cap the ends in order to create a solid)
• segments: 12

rotate_extrude(translate([4,0,0], circle({r: 1, fn: 30, center: true}) ) );
rotate_extrude({fn: 36, startAngle: 45, angle: 180}, translate([4, 0, 0], circle({r: 1, fn: 30, center: true})));
 
rotate_extrude({fn:4}, square({size: [1,1], center: true}).translate([4,0,0]) );
 
rotate_extrude(polygon({points:[ [0,0],[2,1],[1,2],[1,3],[3,4],[0,5] ]}) );
rotate_extrude({fn:4}, polygon({points:[ [0,0],[2,1],[1,2],[1,3],[3,4],[0,5] ]}) );

You can essentially extrude any 2D polygon (circle, square or polygon).