A <?= B equals to A = std::min(A, B) and A <? B is std::min(A, B)
But be careful. This operators aren't from C++ standart. Using them you can get compilation error.
UPD It's an old gcc extension. Now they are removed from compiler.
The G++ minimum and maximum operators (<? and >?) and their compound forms (<?=) and >?=) have been deprecated and are now removed from G++. Code using these operators should be modified to use std::min and std::max instead.
A <?= B equals to A = std::min(A, B) and A <? B is std::min(A, B)
But be careful. This operators aren't from C++ standart. Using them you can get compilation error.
UPD It's an old gcc extension. Now they are removed from compiler.
Source
Thanks !!