Returns an execution context backed by C++ runtime.

This execution context starts a C++ worker assumed to be at path binary_path, serving on port, and constructs a Python remote execution context to talk to this worker.

default_num_clients The number of clients to use as the default cardinality, if thus number cannot be inferred by the arguments of a computation.
max_concurrent_computation_calls The maximum number of concurrent calls to a single computation in the C++ runtime. If nonpositive, there is no limit.
stream_structs The flag to enable decomposing and streaming struct values.

RuntimeError If an internal C++ worker binary can not be found.