struct.cc     :  a struct describing a 2d point
strc11.cc     :  C++11: a struct describing a 2d point

to compile:
c++ -Wall -o struct struct.cc
c++ -Wall -o strc11 strc11.cc -std=c++11

simple   :  2 classes describing a 2d point and a 2d line
cross    :  same classes calling each other
friend   :  same classes calling each other, with "friend" specifier

opera    :  operators with a class describing a 2D vector

except   :  exception handling

