  Using the entire sample of 467 million Y(4S) --> BBbar decays collected with
the BaBar detector at the PEP-II asymmetric-energy B factory at SLAC, we
perform a "GLW" analysis of B+- --> D K+- decays, using decay modes in which
the neutral D meson decays to either CP-eigenstates or non-CP-eigenstates. We
measure the partial decay rate charge asymmetries for CP-even and CP-odd D
final states to be A_CP+ = 0.25+-0.06+-0.02 and A_CP- = -0.09+-0.07+-0.02,
respectively, where the first error is the statistical and the second is the
systematic uncertainty. The parameter A_CP+ is different from zero with a
significance of 3.6 standard deviations, constituting evidence for direct CP
violation. We also measure the ratios of the charged-averaged B partial decay
rates in CP and non-CP decays, R_CP+ = 1.18+-0.09+-0.05 and R_CP- =
1.07+-0.08+-0.04. We infer frequentist confidence intervals for the angle gamma
of the (db) unitarity triangle, for the strong phase difference delta_B, and
for the amplitude ratio r_B, which are related to the B- --> DK- decay
amplitude by r_Be^{i(delta_B-gamma)} = A(B- --> anti-D0 K^-)/A(B- --> D0 K-).
Including statistical and systematic uncertainties, we obtain 0.24<r_B<0.45
(0.06<r_B<0.51) and, modulo 180 degrees, 11.3 degrees < gamma < 22.7 degrees or
80.9 degrees < gamma < 99.1 degrees or 157.3 degrees < gamma < 168.7 degrees
(7.0 degrees < gamma < 173.0 degrees) at the 68% (95%) confidence level.
