SANE_Bool is used for variables that can take one of the two truth values SANE_FALSE and SANE_TRUE. The former value is defined to be 0, whereas the latter is 1.4.1 The C declarations for this type are given below.
#define SANE_FALSE 0 #define SANE_TRUE 1 typedef SANE_Word SANE_Bool;Note that
SANE_Bool is simply an alias of SANE_Word. It
is therefore always legal to use the latter type in place of the
former. However, for clarity, it is recommended to use
SANE_Bool whenever a given variable or formal argument has a
fixed interpretation as a boolean object.