Unmarshal geoJSON []byte to MultiPoint

[mbn18]

This fail at compile

    data := geom.NewMultiPoint(geom.XYZM)
    err := geojson.Unmarshal(readFile(), data)

With error:

cannot use data (variable of type geom.MultiPoint) as type geom.T in argument to geojson.Unmarshal: geom.MultiPoint does not implement geom.T (type *geom.T is pointer to interface, not interface)

The only way I could do it was using type hint:

func readMultiPoint() *geom.MultiPoint {
    var g geom.T
    err := geojson.Unmarshal(readFile(), &g)
    if err != nil {
        panic(err)
    }
    return g.(*geom.MultiPoint)
}

Is there a way to make the geojson.Unmarshal to work with MultiPoint? (or other geom).

[twpayne]

No. When you're unmarshaling GeoJSON you don't know what type of geometry you will get, so you have to check afterwards.

[mbn18]

@twpayne , how should I check the result?

[twpayne]

You can use a type assertion in its two-valued form.