The example code:
string stage_path = "../LOPNET_for_Import/output0"; // A valid LOP node string wrong_path = "../wrong_ref"; // A valid SOP node string non_existing_path = "../foo"; // A non-existing SOP node i@is_stage = usd_isstage(stage_path); // '../LOPNET_for_Import/output0' is a valid stage (Return 1) i@wrong_stage = usd_isstage(wrong_path); // A null node is a valid stage (Return 1) i@non_existing_stage = usd_isstage(non_existing_path); // A non-existing node is a valid stage (Return 1) i@is_prim = usd_isprim(stage_path, "/SimulationData/Sewings/sewing0"); // Try to access a primitive (Return 0) i[]@attrib_test = usd_attrib(stage_path, '/SimulationData/Sewings/sewing0', 'PLIndexPair'); // Try to acces a property (Return 0) i@mesh_type_prim = usd_isprim(stage_path, "/Mesh/Pattern_15382_15382"); // Try to check if it can find a "mesh" type prim (Return 0)