FS#1550 Make Geometry default constructible

Metadata

Property	Value
Reported by	Martin Nolte (nolte@mathematik.uni-freiburg.de)
Reported at	Jan 9, 2015 10:54
Type	Feature Request
Version	2.3
Operating System	Unspecified / All

Description

Geometries are now copy constructible and copy assignable objects. However, in some situations it, like storing geometries in a vector indexed by the index set, a default constructor would be extremely convenient.

As a geometry can always model the identity, there seems no design principle speaking against such default constructibility. Only the return value of "type()" needs to be implementation-defined.

Since nobody will use a default constructed geometry, I would even propose to specify undefined behavior for all methods. This way, implementations simply storing a pointer internally remain trivial.

Are there any reasons not to add this default constructor to the interface?