  While recent progress in quantum hardware open the door for significant
speedup in certain key areas (cryptography, biology, chemistry, optimization,
machine learning, etc), quantum algorithms are still hard to implement right,
and the validation of such quantum programs is achallenge. Moreover, importing
the testing and debugging practices at use in classical programming is
extremely difficult in the quantum case, due to the destructive aspect of
quantum measurement. As an alternative strategy, formal methods are prone to
play a decisive role in the emerging field of quantum software. Recent works
initiate solutions for problems occurring at every stage of the development
process: high-level program design, implementation, compilation, etc. We review
the induced challenges for an efficient use of formal methods in quantum
computing and the current most promising research directions.
