This is doable. The message would sould like this:
difference between var1 {<value>} and var2 {<value>} is x% and exceeds e%
Good. This one is quite pressing for me, as there are some failing tests I can't diagnose otherwise :-/
2) Can we please have a BOOST_CHECK_EPSILON, that uses a whole number of epsilon as the tolerance? IMO BOOST_CHECK_CLOSE should have been written this way to begin with, but it's too late now
Actually it was this way originally. It was causing constant confusion with absolute comparison. I thought persents will bring better message. Unfortunately many users since then indicated that original version (for those who knew how to use it) was better. If there is a general consensus I am willing to rollback. Or we could introduce a new tool.
Has to be a new tool, too much would break otherwise, I like the name BOOST_CHECK_CLOSE_EPSILON suggested elsewhere.
Again it should print out the actual relative error as a multiple of epsilon as well as the input values. Actually while we're at it the absolute error may be useful to have in some situations as well :-)
This one already exists: BOOST_CHECK_SMALL( v, epsilon )
Sorry that's not what I meant, I meant when BOOST_CHECK_CLOSE or BOOST_CHECK_CLOSE_EPSILON fail then they should print out: The two input values. The max relative error permitted. The actual relative error found. The actual absolute error found. More information is a good thing in this case :-) Regards, John.