Question

I wish to compare index of an element in a std::vector to an unsigned value. If I directly compare like;

if(std::distance(...)>min_distance) // true for some

I just get a warning, but works fine. However, to get rid of the warning, if I cast min_distance to int, I do not get any comparison result (although there is)

if(std::distance(...)>(int)min_distance) // never true

What is the exact problem?

Answer 1

Try:

if ( std::abs( std::distance( ... ) ) > min_distance )

std::distance returns a signed value. I am assuming you are trying to get the distance in such a way that -2 AND 2 would be considered as 2. The abs function gives you the absolute value which means that whatever the sign of the input, you always get a positive value back.