It’s difficult in practice to distinguish between general and lib-specific flags, becuase one developer thinks is general does not always be considered the same

It’s difficult in practice to distinguish between general and lib-specific flags, becuase one developer thinks is general does not always be considered the same by another, and you either need to magically read developers’ minds, or make a decision somewhere and leave a portion of your users grumpy. This is especially difficult for an ecosystem as established as C++ since there are too many interest groups all want different things. And more good luck if you don’t control the compiler—whatever you decide may end up wrong tomorrow because the compiler developers change their minds, and of course you take all the blame because everything works except when the user uses your tool.