if (TF2Econ_GetItemEquipRegionMask(equippedItemD ef) & TF2Econ_GetItemEquipRegionMask(newItemDef)) {
// the result being non-zero means that the equip regions for these two item definitions overlap, so `equippedCosmetic` needs to be detached
}
Perfect! That's exactly what I needed. Thanks nosoop!