\label{fig:baer}
(Modified from Ref.~\cite{Baer_2013}). Statistical uncertainties on CP-conserving top-quark form factors expected at the ILC (blue) and the LHC (red). The figure was modified to include the projections from the FCC-ee. The results for the LHC assume an integrated luminosity of 300\,${\rm fb}^{-1}$ and a centre-of-mass energy of 14\,TeV. The results for the ILC assume an integrated luminosity of  500\,${\rm fb}^{-1}$ at $\sqrt{s} = 500$\,GeV, and beam polarizations of ${\cal P} = \pm 0.8$, ${\cal P}^\prime = \mp 0.3$. The ILC projections are obtained from the measurements of the total top-quark pair production cross section, together with the top-quark forward-backward and the helicity asymetries. The FCC-ee projections are obtained at $\sqrt{s}=360$\,GeV, with unpolarized beams and with an integrated luminosity of 2.6\,${\rm ab}^{-1}$, from the sole lepton angular and energy distributions.