Attached is the test file for a proposed new defect macro, BOOST_NO_IMPLICIT_BOOL_CONVERSION. This identifies compilers (such as Borland) that do not always convert expressions to bool as required by 5.14/5.15 and elsewhere. The workaround is fairly simple - detect the bad compiler and add an additional static_cast<bool>( ) around the (sub)expression. This only really catches classes relying on the convertible-to-unspecified-bool-type idiom. The test results I am posting have applied this workaround in a number of places, and obviously I would prefer to post those patches with a defect macro rather than compiler (and version) specific workarounds. Note: the tests checks all 'boolean contexts', not just the two or three that fail with Borland. I don't know if this will catch any other compilers. As ever, I am open to suggestions for a better name. -- AlisdairM