values[idx] = reflect.New(reflect.PtrTo(field.FieldType)).Interface()
				continue
			}
			values[idx] = new(interface{})
		}
	} else if len(columnTypes) > 0 {
		for idx, columnType := range columnTypes {
			if columnType.ScanType() != nil {
				values[idx] = reflect.New(reflect.PtrTo(columnType.ScanType())).Interface()
			} else {
				values[idx] = new(interface{})
			}
		}

	// types of the address fields are identical (where identicalness is
	// decided by the CSE pass).
	c := testConfig(t)
	t1 := c.config.Types.UInt64.PtrTo()
	t2 := c.config.Types.UInt32.PtrTo()
	fun := c.Fun("entry",
		Bloc("entry",
			Valu("start", OpInitMem, types.TypeMem, 0, nil),
			Valu("sb", OpSB, c.config.Types.Uintptr, 0, nil),
			Valu("v", OpConstBool, c.config.Types.Bool, 1, nil),

    (Load <t.FieldType(0)> (OffPtr <t.FieldType(0).PtrTo()> [0]             ptr) mem)
    (Load <t.FieldType(1)> (OffPtr <t.FieldType(1).PtrTo()> [t.FieldOff(1)] ptr) mem)
    (Load <t.FieldType(2)> (OffPtr <t.FieldType(2).PtrTo()> [t.FieldOff(2)] ptr) mem))
(Load <t> ptr mem) && t.IsStruct() && t.NumFields() == 4 && CanSSA(t) =>
  (StructMake4
    (Load <t.FieldType(0)> (OffPtr <t.FieldType(0).PtrTo()> [0]             ptr) mem)

    {!> ../../../docs_src/query_params/tutorial002.py!}
    ```

Nesse caso, o parâmetro da função `q` será opcional, e `None` será o padrão.

!!! check "Verificar"
    Você também pode notar que o **FastAPI** é esperto o suficiente para perceber que o parâmetro da rota `item_id` é um parâmetro da rota, e `q` não é, portanto, `q` é o parâmetro de consulta.


## Conversão dos tipos de parâmetros de consulta

func badlinkname_rtype_Size(*rtype) uintptr

//go:linkname badlinkname_rtype_String reflect.(*rtype).String
func badlinkname_rtype_String(*rtype) string

//go:linkname badlinkname_rtype_ptrTo reflect.(*rtype).ptrTo
func badlinkname_rtype_ptrTo(*rtype) *abi.Type

//go:linkname badlinkname_Value_pointer reflect.(*Value).pointer

	// pointer bitmap for arguments.
	inRegPtrs := abi.IntArgRegBitmap{}

	// Compute abiSeq for input parameters.
	var in abiSeq
	if rcvr != nil {
		stkStep, isPtr := in.addRcvr(rcvr)
		if stkStep != nil {
			if isPtr {
				stackPtrs.append(1)
			} else {
				stackPtrs.append(0)
			}
		} else {
			spill += goarch.PtrSize
		}
	}
	for i, arg := range t.InSlice() {

var ptrMap sync.Map // map[*rtype]*ptrType

// PtrTo returns the pointer type with element t.
// For example, if t represents type Foo, PtrTo(t) represents *Foo.
//
// PtrTo is the old spelling of [PointerTo].
// The two functions behave identically.
//
// Deprecated: Superseded by [PointerTo].
func PtrTo(t Type) Type { return PointerTo(t) }

								b2 = b3
							}
						}
						toPrint = append(toPrint, fmt.Sprintf("\t%s: %s", string(b), string(b2)))
					} else if c.Bool("combine") && isPart.MatchString(file.Name) {
						// name := isPart.FindString(file.Name)
						name := strings.ReplaceAll(file.Name, ":", "_")
						r, err := file.Open()
						if err != nil {
							return err
						}
						all, err := io.ReadAll(r)

	// check if the receiver is set (we cannot just look for non-nil obj.typ).
	if sig, _ := obj.typ.(*Signature); sig != nil && sig.recv != nil {
		_, isPtr := deref(sig.recv.typ)
		return isPtr
	}

	// If a method's type is not set it may be a method/function that is:
	// 1) client-supplied (via NewFunc with no signature), or
	// 2) internally created but not yet type-checked.

		}
		var e Node = NewLinksymExpr(pos, name.LinksymABI(abi), types.Types[types.TUINTPTR])
		e = NewAddrExpr(pos, e)
		e.SetType(types.Types[types.TUINTPTR].PtrTo())
		e = NewConvExpr(pos, OCONVNOP, types.Types[types.TUINTPTR], e)
		e.SetTypecheck(1)
		return e
	}
	// fn is not a defined function. It must be ABIInternal.