[erics118]

What?

adds chuds::WireBody concept that defines what make_message and body_as
can accept. ie, opt-in marker, trivially copyable, standard layout, size is at most kMaxBody, no padding, no pointer

previously we would just require it to be is_standard_layout_v and is_trivially_copyable_v, as has_unique_object_representations doesn't work for floats.

we now have some compiler magic:

template <class T>
consteval bool has_no_padding_or_pointers() {
    for (const auto byte : std::bit_cast<std::array<unsigned char, sizeof(T)>>(T{})) {
        static_cast<void>(byte);
    }
    return true;
}

at compile time, we default construct an instance of T, and loop over each byte of it. we cannot bit_cast pointers at compile time. we also can't read a byte with an indeterminate at compile time. so, both pointers and padding now properly cause compile errors

rename chuds_wire_body to is_chuds_wire_body to read as a yes/no flag

added tests to assert WireBody works properly, and that bad bodies fail to compile through make_message and body_as

Why?

handles more cases that should be handled: pointers and padding. it would previously cause garbage data to be sent.

follows idiomatic c++

Verification Evidence

the tests pass.

we assert that the WireBody concept works for the shapes of structs that we want it to support, and it properly fails for the shapes that it shouldnt' work for.

we also test that things that should fail to compile do indeed fail to compile

ci also passes.

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.

An organization owner can choose the repository organization as the billing source for reviews requested by members with a paid Copilot license. Learn about Copilot code review billing.

[erics118]

:/

[danielsapiary]

Small and well-documented and reasoned. Nice