#define macro1 test
#defplus macro1 another test
Next line should be "test another test":
macro1

#define macro2 this that
#defplus macro2 this
#defplus macro2 this
Next line should be "this that this this"
macro2

#defplus macro3 one good macro
#defplus macro3 deserves another
Next line should be "one good macro deserves another"
macro3

#defplus macro4 this won't appear
#undef macro4
#defplus macro4 a new day
Next line should be "a new day"
macro4
