Custom type struct

[gebv]

How to add a custom type that would be not causing an error Formater? This is the interface?

ex.

CREATE TABLE objects (
object_id serial NOT NULL PRIMARY KEY,
tags text[],
);

INSERT INTO objects(tags) VALUES
    ('{a, b, c}'),
    ('{a, c}'),
    ('{c}'),
    ('{b}');

var model = struct {
        ObjectId int64
        Tags  StringSlice
    }{}

QueryOne(&model, "SELECT object_id, tags FROM objects WHERE object_id = ?", 1)
// ok

model.Tags.Del("a")
model.Tags.Del("b")
model.Tags.Add("d")

QueryOne(&model, "UPDATE objects SET tags = ?tags WHERE object_id = ?object_id", model)
QueryOne(&model, "UPDATE objects SET tags = ? WHERE object_id = ?", model.Tags, model.ObjectId)
// Error: Format(unsupported StringSlice)

QueryOne(&model, "UPDATE objects SET tags = ? WHERE object_id = ?", []string(model.Tags), model.ObjectId)
// It'ok, but isn't convenient to use

type StringSlice []string

func (c *StringSlice) Del(str string) {
    str = strings.TrimSpace(str)

    if !c.IsExist(str) {
        return
    }

    for index, value := range *c {

        if bytes.Equal([]byte(str), []byte(value)) {
            (*c)[index] = (*c)[len((*c))-1]
            (*c) = (*c)[:len((*c))-1]

            return
        }
    }
}

func (c *StringSlice) IsExist(str string) bool {
    str = strings.TrimSpace(str)

    for _, value := range *c {

        if bytes.Equal([]byte(str), []byte(value)) {

            return true
        }
    }

    return false
}

func (c *StringSlice) Add(str string) {
    str = strings.TrimSpace(str)

    if len(str) == 0 {
        return
    }

    if !c.IsExist(str) {
        *c = append(*c, str)
    }
}

[vmihailenco]

@gebv should be fixed in master. Thanks for the report!