Would you say it's similar to the problems that modern c++ has with older (pre c++-11 even) code? I quite like modern c++ and use it along with rust, but haven'

Would you say it's similar to the problems that modern c++ has with older (pre c++-11 even) code? I quite like modern c++ and use it along with rust, but haven't done a lot with older code bases (my definition being before the c++11 standard became commonplace) . We enforce it at work, although we have a few c libraries in the mix, that we plan on "rewriting" when "we" get the chance (I don't see that happening :) ) . Just curious. I have done nothing in php other than a couple of silly examples and setting up a couple servers to use wordpress.