If you are building 64-bit binaries, you must pass the define ODBC64. The example Application provides a demonstration of this. See the installed file example.txt for details.
You must also include the correct compiler switches if you are building 64-bit binaries. For instance, to build example, you would use:
g++ -o example -DODBC64 -I../include example.c -L../lib -lodbc -lodbcinst -lc
