Elements of groups, rings and fields are stored in the
element_t data type. Variables of
this type must be initialized before use, and should be cleared
after they are no longer needed.
The element_ functions must be
used with caution. Just as division by zero does not make sense
for integers, some operations may not make sense for particular
elements. For example, in a ring, one cannot in general invert
elements.
Another caveat is that many of these functions assume their arguments come from the same ring, group or field. No implicit type casting is performed.
For debug builds, turn on run-time checks by defining
PBC_DEBUG before including
pbc.h:
#define PBC_DEBUG #include <pbc.h>
Also, when PBC_DEBUG is
defined, the following macros are active. Normally they are
replaced with empty statements.
PBC_ASSERT(expr, msg)
Macro: if
exprevaluates to 0, printmsgand exit.
PBC_ASSERT_MATCH2(a, b)
Macro: if elements
aandbare from different fields then exit.
PBC_ASSERT_MATCH3(a, b, c)
Macro: if elements
a,bandcare from different fields then exit.