marshmallow extension that adds a custom field designed for polymorphic types, allowing defining schemas that say "this field accepts anything of type X". This field should support the same properties as other marshmallow fields, including "required", "allow_none", and "many".

DOLFIN is the Python and C++ interface of the FEniCS project for the automated solution of differential equations, providing a consistent PSE (Problem Solving Environment) for solving ordinary and partial differential equations. Key features include a simple, consistent and intuitive object-oriented API; automatic and efficient evaluation of variational forms; automatic and efficient assembly of linear systems; and support for general families of finite elements.

This is the GNU C++ compiler, a fairly portable optimizing compiler for C++.