Reads a field identified by a FieldInfo from a C structure or union.
This only handles fields of simple C types. It will fail for a field of a composite type like a nested structure or union even if that is actually readable.
| mem |
pointer to a block of memory representing a C structure or union |
| value |
a Argument into which to store the value retrieved |
| field_info |
|
true if reading the field succeeded, otherwise false |