Worth noting you should probably disable -Werror for distribution if you expect users to compile your code. They aren't going to fix your error for you and you can't know what warnings will be added to future compilers, nor what previous compiler versions marked as errors. Among many other people saying the same thing see [0] if you don't trust me.
Also IMO you often want to explicitly disable a few of those from -Wall and -Wextra -- Looking at the last c++ project I wrote, I turned off a few things like `-Wno-unused-parameter` for example.
As you get further into a project you tend to need subtler tools. But for the rough work when starting out, my preference is to be stricter, which can be relaxed as necessary, rather than starting out lax and reaching a point where tightening becomes Sisyphean.
Which does actually turn on all warnings (so you'll probably want to add things like -Wno-unused -Wno-padded).
Under gcc, '-Wall -Wextra -Wpedantic' does not enable all warnings. There are still more than 40 flags you have to give if you really want all of them.
Zcash, for example, is built with `-Werror` (edit: not `-Wall`, but we're working on that). So this is absolutely feasible on a Bitcoin-derived codebase.
