Add AssignTo to pgtype.Timestamptz

Also handle infinity for pgtype.Date

conn.go

@@ -280,12 +280,13 @@ func (c *Conn) connect(config ConnConfig, network, address string, tlsConfig *tl
 	c.closedChan = make(chan error)
 
 	c.oidPgtypeValues = map[OID]pgtype.Value{
-		BoolOID:      &pgtype.Bool{},
-		DateOID:      &pgtype.Date{},
-		Int2OID:      &pgtype.Int2{},
-		Int2ArrayOID: &pgtype.Int2Array{},
-		Int4OID:      &pgtype.Int4{},
-		Int8OID:      &pgtype.Int8{},
+		BoolOID:        &pgtype.Bool{},
+		DateOID:        &pgtype.Date{},
+		Int2OID:        &pgtype.Int2{},
+		Int2ArrayOID:   &pgtype.Int2Array{},
+		Int4OID:        &pgtype.Int4{},
+		Int8OID:        &pgtype.Int8{},
+		TimestampTzOID: &pgtype.Timestamptz{},
 	}
 
 	if tlsConfig != nil {

pgtype/date.go

@@ -39,7 +39,7 @@ func (d *Date) ConvertFrom(src interface{}) error {
 func (d *Date) AssignTo(dst interface{}) error {
 	switch v := dst.(type) {
 	case *time.Time:
-		if d.Status != Present {
+		if d.Status != Present || d.InfinityModifier != None {
 			return fmt.Errorf("cannot assign %v to %T", d, dst)
 		}
 		*v = d.Time

pgtype/timestamptz.go

@@ -3,6 +3,7 @@ package pgtype
 import (
 	"fmt"
 	"io"
+	"reflect"
 	"time"
 
 	"github.com/jackc/pgx/pgio"
@@ -40,6 +41,39 @@ func (t *Timestamptz) ConvertFrom(src interface{}) error {
 	return nil
 }
 
+func (t *Timestamptz) AssignTo(dst interface{}) error {
+	switch v := dst.(type) {
+	case *time.Time:
+		if t.Status != Present || t.InfinityModifier != None {
+			return fmt.Errorf("cannot assign %v to %T", t, dst)
+		}
+		*v = t.Time
+	default:
+		if v := reflect.ValueOf(dst); v.Kind() == reflect.Ptr {
+			el := v.Elem()
+			switch el.Kind() {
+			// if dst is a pointer to pointer, strip the pointer and try again
+			case reflect.Ptr:
+				if t.Status == Null {
+					if !el.IsNil() {
+						// if the destination pointer is not nil, nil it out
+						el.Set(reflect.Zero(el.Type()))
+					}
+					return nil
+				}
+				if el.IsNil() {
+					// allocate destination
+					el.Set(reflect.New(el.Type().Elem()))
+				}
+				return t.AssignTo(el.Interface())
+			}
+		}
+		return fmt.Errorf("cannot assign %v into %T", t, dst)
+	}
+
+	return nil
+}
+
 func (t *Timestamptz) DecodeText(r io.Reader) error {
 	size, err := pgio.ReadInt32(r)
 	if err != nil {