Here are the classes, structs, unions and interfaces with brief descriptions:

Nlsst
Nsphgeom
N_continue_class
CRegion
CCircle
CBox
CConvexPolygon
N_healpixPixelization
CHealpixPixelization
Ndetail
CPixelFinder
Npixelization_abc
CPixelizationABC
CAngle
CAngleInterval	AngleInterval represents closed intervals of arbitrary angles
CBigInteger
CBox
CBox3d
CChunker
CCircle
CCompoundRegion
CConvexPolygon
CEllipse
CHtmPixelization
CIntersectionRegion
CInterval
CInterval1d
CIvoaStcsNotImplemented
CLonLat
CMatrix3d	A 3x3 matrix with real entries stored in double precision
CMq3cPixelization
CNormalizedAngle
CNormalizedAngleInterval
CPixelization
CQ3cPixelization
CRangeSet
CIterator
CRegion
CSubChunks
CTriState
CUnionRegion
CUnitVector3d
CVector3d	Vector3d is a vector in ℝ³ with components stored in double precision
Npybind11
Ndetail
Ctype_caster< lsst::sphgeom::Relationship >
Ctype_caster< lsst::sphgeom::TriState >