Is there a way the C++ STL Maps support this, since lower_bound and upper_bound on maps strictly return the value greater than the passed value.
Use case I have a map with times as keys in a sorted manner so in a MAP
time t1 = value1
time t2 = value2
time t2.5 = value3
In this case if I pass to this MAP t2.3 then it should give me value2. Does doing a lower_bound on the map and going back one element equivalent to the "returning greatest key strictly less than given key" i.e
iterator = map.upper_bound(2.3)
and then
iterator--;
Best Answer
Yeah, lower_bound can be used for that, i've seen it before and used it like that.
Would actually return the greatest, yet smaller (if it != map.begin() was true) one. If it was at .begin, then there is no smaller key. Nice idea from the comments is to return
.end
if there is no element that's less and pack this stuff into a function:The template should work for
std::set
too.