Please double check that this won't cause issues later...

Please mention the null character so the -3 makes sense

... here for example

Now a <260 chars>.pwned name will be fine.

I think what you want here is constexpr

Whatever the type is, if you go from signed to unsigned you need to be sure that it is safe when using the - operator (which is done a few lines below) because this is a behavior change.
What is the rational behind this change (which seems unrelated to what the summary describe as the intent for this diff) ?

Mind changing k to ok while you're at it ?

There is a type for pointer arithmetic: https://en.cppreference.com/w/cpp/types/ptrdiff_t

2 questions:

• Is the static keyword necessary ?
• Why not make them all constexpr ?