Interesting and I hope eventually useful

TTBOMK, its plans for C++ modules are "none", so its future on that front is definitely questionable if you ask me (though it is really more of an `automake` thing than `autoconf`, but they're so intertwined…). There's one enterprising developer that's been looking at making it more "native" to GCC (but I haven't seen any news on that front for over a month), but this means (more or less) embedding a build system in the compiler which is unlikely to really be all that effective or standard between implementations.