Function UtmProjection.isValid

True when this value represents a supported prepared UTM projection.

bool isValid() const pure nothrow @nogc @property @safe;

Example

Example checking a prepared UTM projection. 

import geodesy;
const projection = UtmProjection!double.fromZone(
    wgs84!double(), UtmZone.fromNumber(33), UtmHemisphere.north);
assert(projection.isValid);