Replace iox::byte_t with std::byte

[elBoberido]

Brief feature description

Currently iox::byte_t is a uint8_t. Having a distinct type like C++17 std::byte helps to prevent issues with accidentally passing a uint8_t where a iox::byte_t is expected.

Detailed information

A drop in replacement for std::byte with C++14 is not possible since the compiler does not treat an enum class byte : uint8_t {}; like an unsigned char and therefore the strict aliasing rule cannot be applied. With C++17 beside char and unsigned char also std::byte can be used. See also the Type aliasing section in reinterpret_cast.

Tasks

• consolidate all byte_t types
• rename iox::byte_t to iox::byte
• use std::byte when switching to C++17

[elfenpiff]

@elBoberido this is a cool idea and I think we already have - maybe even multiple - definitions of that type.

Why an enum class and not a NewType?

[elBoberido]

@elfenpiff simple solutions for simple problems ;)

The enum class is sufficient for this since we do not want to do any arithmetic with the type. We just want something which is 1 byte large and does not do anything.