IDFMT

[Anjiang-Wei]

The example code shown in the manual heavily uses IDFMT, e.g.,
https://github.com/StanfordLegion/legion-manual/blob/master/Examples/Mapping/machine/machine.cc#L53

printf("Mapper %s: has affinity to memory " IDFMT "\n", get_mapper_name(), it->id);

Readers can be quite confused about what IDFMT is. It's actually defined here in legion/runtime/realm/realm_c.h
https://github.com/StanfordLegion/legion/blob/stable/runtime/realm/realm_c.h#L34

typedef unsigned long long realm_id_t;
#define IDFMT "%llx"

I am not sure whether we would want to add a subscript to explain IDFMT somewhere in the manual (e.g, when IDFMT first appears).

[lightsighter]

Really the right answer will involve this Legion issue:
StanfordLegion/legion#84
I'm planning to address this after the control replication merge so all Legion objects can be passed to a c++ standard output stream and then we won't need to rely on things like IDFMT anymore.