[flebron]

Underscores are already being used for user defined literals.

[drdaeman]

User-defined literals can't generally start with a digit, so it should be perfectly fine to allow 1_000_000 syntax for 1000000. Or I'm forgetting something?

[jeorgun]

Hexadecimal numbers, probably. 0x001_f05 would be ambiguous.

[AnimalMuppet]

I don't think that's it. 0x001_f05 starts with 0, which is still not something an identifier can do.

[plorkyeran]

0x001_f05 could be a UDL named f05 which should be passed 0x001.

[AnimalMuppet]

Oh. UDLs are a new one to me. I didn't know that was in the language.

I stand corrected.

[nightcracker]

Where do you get this information from, because it's entirely incorrect.