Some time ago I met confusing C ternary operator usage
return timeout ?: 1;
It turned out to be a GNU "Conditionals with Omitted Operands"
C extension. The list of "Extensions to the C Language Family" can be found here.This page is worth reading. For example, getting
the address of a label defined in the current function (or a containing
function) with the unary operator `&&'. The value has type
void *. This value
is a constant and can be used wherever a constant of that type is valid.