<enum name="Enum1" encodingType="uint8">
    <validValue name="Val1">0</validValue>
    <validValue name="Val2">1</validValue>
    <validValue name="Val3">2</validValue>
</enum> 

<message name="Msg1" id="1" description="TestMessage">
    <field name="field1" id="20" type="Enum1" presence="constant" valueRef="Enum1.Val2"/>
</message>

Enum1::Value field1() const SBE_NOEXCEPT
{
    return Enum1::Value::Val2;
}

static SBE_CONSTEXPR std::uint16_t sbeBlockLength() SBE_NOEXCEPT
{
    return (std::uint16_t)1;
}