[andreyv]

std::uint8_t is not required to exist on a particular implementation, for example, if the machine byte is not 8-bit.

std::byte still seems pretty useless, though. There already is a built-in type for designating bytes: unsigned char.

[evanmoran]

It's for clarity about fixed size bitwise operations. Here's how the spec doc describes it's motivation:

(http://open-std.org/JTC1/SC22/WG21/docs/papers/2017/p0298r3....)

Motivation and Scope:

Many programs require byte-oriented access to memory. Today, such programs must use either the char, signed char, or unsigned char types for this purpose. However, these types perform a “triple duty”. Not only are they used for byte addressing, but also as arithmetic types, and as character types. This multiplicity of roles opens the door for programmer error – such as accidentally performing arithmetic on memory that should be treated as a byte value – and confusion for both programmers and tools.

Having a distinct byte type improves type-safety, by distinguishing byte-oriented access to memory from accessing memory as a character or integral value. It improves readability. Having the type would also make the intent of code clearer to readers (as well as tooling for understanding and transforming programs). It increases type-safety by removing ambiguities in expression of programmer’s intent, thereby increasing the accuracy of analysis tools.

[userbinator]

such as accidentally performing arithmetic on memory that should be treated as a byte value

My reaction to that can be summed up succinctly as "WTF!?" The whole point of uint8_t or (signed/unsigned) char is an 8-bit quantity that you can do arithmetic and bitwise operations on. To put it more bluntly, "have C++ programmers forgotten how computers work?"

The proposed solution is to add yet another same-yet-subtly-different type, with its own set of same-yet-subtly-different rules? If anything that would cause even more confusion due to the complexity it causes in interactions with all the other parts of the language.

IMHO this "let's do everything we can to stop people from even the very slightest change of possibly doing something wrong" line of thinking is ultimately unproductive... and actually rather dystopian. The end-result is quite scary to contemplate.

(The fact that an 11-page, text-only PDF somehow turns out to be over 800KB is somewhat less disturbing, but still notable.)

[SamReidHughes]

It's just a bit of type safety. Calm down.