Comment by bregma
There are a handful of commercial offerings of C++ conformance test suites. They're all generally around 40000 euro for an evaluation copy (more for an actual full licensed copy), none are 100% complete, and we continually find bugs in tests.
You're not going to find some hobbyist coming up with a useful conformance or coverage test suite for free. It's intensive, expensive, and arduous.
Such things are mandatory, however, if you are a C++ vendor targeting ISO 26262 or IEC 61508 or similar -- basically, software that could kill you if it's done wrong. It's a niche with money and motivation.