Header::operator [] (const char name[]) const
{
    AttributeMap::const_iterator i = _map.find (name);

    if (i == _map.end())
	THROW (IEX_NAMESPACE::ArgExc, "Cannot find image attribute \"" << name << "\".");

    return *i->second;
}
Header::operator [] (const char name[]) const
{
    AttributeMap::const_iterator i = _map.find (name);

    if (i == _map.end())
	THROW (IEX_NAMESPACE::ArgExc, "Cannot find image attribute \"" << name << "\".");

    return *i->second;
}