A.h
A.cc
B.h
B.cc
testConv.cc  :  implicit or explicit type conversion with constructors

Pippo.h
Pippo.cc
testOper.cc  :  implicit type conversion with operator

Pluto.h
Pluto.cc
testExpc.cc  :  C++11: explicit type conversion with operator

to compile:
c++ -o testConv testConv.cc A.cc B.cc
c++ -o testOper testOper.cc Pippo.cc
c++ -o testExpc testExpc.cc Pluto.cc -std=c++11
