Two of the three operations in impl() return void, among them the
most common one, call(). Having impl() return bool prevents tail-
call optimisations for these.
Fix by passing the bool return value for Compare as an out-parameter.
Results in a nice decrease in text size
(GCC 4.8-pre -O2 -std=c++11, stripped):
text data bss dec hex filename
507343 13984 48 521375 7f49f tst_qobject (old)
505551 13984 48 519583 7ed9f tst_qobject (new)
Reported-by: Thiago Macieira <thiago.macieira@intel.com>
Change-Id: I7538c5b3f0992970c089e44f07244e6b62794a1d
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
15b5b28425