spot
2.7

A class implementing Kleene's threevalued logic. More...
#include <spot/misc/trival.hh>
Public Types  
enum  value_t : repr_t { no_value = 1, maybe_value = 0, yes_value = 1 } 
typedef signed char  repr_t 
Public Member Functions  
constexpr  trival (bool v) 
constexpr  trival (value_t v) 
constexpr bool  is_known () const 
Is true or false, but not maybe. More...  
constexpr bool  is_maybe () const 
constexpr bool  is_true () const 
constexpr bool  is_false () const 
constexpr value_t  val () const 
constexpr  operator bool () const 
constexpr trival  operator! () const 
Static Public Member Functions  
static trival  from_repr_t (repr_t v) 
static constexpr trival  maybe () 
A class implementing Kleene's threevalued logic.
https://en.wikipedia.org/wiki/Threevalued_logic#Kleene_and_Priest_logics

inline 
Is true or false, but not maybe.