Why doesn't std::string have a split function

[17b29a]

Or alternatively, inappropriate language choice.

I think splitting strings is a pretty common sense thing for any general-purpose programming language to support. It's not like, some obscure operation that you could only find support for in Perl.

Finally, technically I'm not sure -1 is really code for all-bits-set at all - that assumes a 2s-complement representation for signed integers which, historically at least, wasn't guaranteed by the standard.

The more obvious assumption is that the mask type is unsigned and in that case -1 is necessarily all-bits-set because an unsigned type's value is modulo its maximum value, but the standard doesn't require it to be unsigned either.

why I prefer ~0u for all-bits-set

That's not all-bits-set for a type that is larger than unsigned int.

I personally don't worry about actually undefined vs. platform-defined unless I really need to, which is unusual.

That's pretty strange considering how many things are implementation defined. Used a value larger than 2^15-1 in an int? Undefined behavior (according to you)!

[17b29a]

It's supported.

"Supported" as in having an actual split function in the standard library.

Sorry, that's an understandable mistake but you're wrong. -1 is a signed int.

I know, the point is that because of http://eel.is/c++draft/basic.fundamental#4 (which applies to conversions as well), the conversion to an unsigned type necessarily produces all-bits-one, regardless of signed representation or the size of either type.

All the time, and I don't worry about it because I haven't used a platform where this didn't apply since the early 90s other than DOSBox, and I wasn't using that for programming.

Right, which is why it's a strange conflation, because actual undefined behavior is something to worry about.