stars inevitably leads to the formation of a metastable object, which we dub the binary-merger product or BMP. Depending on the total mass and mass ratio of the binary, the BMP can either be a supramassive neutron star (SMNS), that is, a star with mass above the maximum mass for nonrotating configurations $M_{_{\rm TOV}}$ but below the maximum mass for uniformly rotating configurations $M_{\rm max}$, with $M_{\rm max} \simeq (1.15-1.20)\,M_{_{\rm TOV}}$ [@Lasota1996]; a hypermassive neutron star (HMNS), that is, a star more massive than a SMNS; or a black hole[^1].

The general-relativistic hydrodynamical modelling of binary neutron stars has seen very considerable progress over the last decade (see, [e.g., ]{}Refs. [@Shibata99d; @Baiotti08; @Anderson2007]), and it has now reached a rather mature state. In fact, it is presently possible to calculate inspiral waveforms having a phase accuracy comparable to that of binary black-hole simulations thanks to the use of high-order methods with high-order convergence rates [@Radice2012a; @Radice2013b; @Radice2015] or of very high-resolution and long inspirals [@Kyutoku2014; @Bernuzzi2015]. At the same time, the space of parameters is also being carefully investigated, both in terms of the variety of the EOSs considered [@Hotokezaka2013c; @Takami2014; @Takami2015], and of the treatment of radiative losses via 