Primitive types

Extract or clear the lowest bit

x&(x-1) clears the lowest bit. x&~(x-1) extract the lowest bit.

header <limits>

numerical_limits<int>::min()
numerical_limits<float>::max()

numerical_limits<doubel>::infinity() 
Returns the special value "positive infinity", as represented by the floating-point type T. Only meaningful if std::numeric_limits<T>::has_infinity == true.