Stable Numerics Subroutine Library
Programming Reference Manual
Version 1.2 DD-00006-012

5.2.8 Status functions

bool is_empty() const; 
bool is_whole() const; 
bool is_signed() const; 
bool is_bounded() const; 
bool is_singleton() const; 
bool is_okay() const; 
 
bool has_zero() const;

These member functions inquire the current status of the interval object.

is_empty()


Whether the interval is empty, that is whether A∈ IR is a= a= ∅.

is_whole()


Whether the interval spans the whole R, that is whether for A ∈ IR is a= -∞ ∧a-=∞.

is_signed()


Whether the interval contains a sign, that is for A ∈IR defined as sgn(a)= sgn(a). It is of note that for this definition it is considered that -0 ̸=0.

is_singleton()


Whether the interval represents a single value in R, that is for A∈ IR defined as a= a⇔ a,a∈ R.

is_okay()


Determines whether the interval is normalized, if false the interval must be normalized with the respective functions.

has_zero()


Determines whether the interval contains a zero, i.e. whether for a given interval A ∈IR it is true that ±0∈ A, where this function will return true if either or both of -0 and 0 are in A.