SharedPreference Delegate extension (Kotlin)

DelegatesExt.kt

object DelegatesExt {
    fun <T : Any> preference(context: Context, name: String, default: T)
            = Preference(context, name, default)
}

class Preference<T>(val context: Context, val name: String,
                    val default: T) : ReadWriteProperty<Any?, T> {
                    
    companion object {
        val PREF_NAME: String = "chameleon"
    }
    
    val prefs by lazy { context.getSharedPreferences(PREF_NAME, Context.MODE_PRIVATE) }
    
    override fun getValue(thisRef: Any?, property: KProperty<*>): T {
        return getPreference(name, default)
    }
    
    override fun setValue(thisRef: Any?, property: KProperty<*>, value: T) {
        putPreference(name, default)
    }
    
    @Suppress("UNCHECKED_CAST")
    private fun <U> getPreference(name: String, default: U): U = with(prefs) {
        val res: Any = when (default) {
            is Long -> getLong(name, default)
            is String -> getString(name, default)
            is Int -> getInt(name, default)
            is Boolean -> getBoolean(name, default)
            is Float -> getFloat(name, default)
            else -> throw IllegalArgumentException("This type can be saved into Preferences")
        }
        res as U
    }
    
    private fun <U> putPreference(name: String, value: U) = with(prefs.edit()) {
        when (value) {
            is Long -> putLong(name, value)
            is String -> putString(name, value)
            is Int -> putInt(name, value)
            is Boolean -> putBoolean(name, value)
            is Float -> putFloat(name, value)
            else -> throw IllegalArgumentException("This type can be saved into Preferences")
        }.apply()
    }
}

Bug in the 20 line. should be: putPreference(name, value)