Fully decomposed compost becomes humus which is ideal for growing vegetables-- but, again, humus is fully decomposed organic matter. You would probably be best to mix the topsoil in your garden with your not yet fully decomposed compost to get your raised beds going--50:50. Aged but not fully decomposed compost will likely be too light to grow in -- meaning, in part, it may not be moisture retentive.

Here is a link that might be useful: HarvestToTable.com