Function Geodesic.isValid

True when this solver represents the supported ellipsoid profile.

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

Example

Example checking whether a geodesic solver is prepared. 

import geodesy;
assert(Geodesic!double.fromEllipsoid(wgs84!double()).isValid);
assert(!Geodesic!double.init.isValid);