Zig version 0.15.1

The Zig project has
announced version 0.15.1 of the language. The release, much like the
last one, includes incremental progress toward the goal of completely dropping LLVM and improving compile time, as well as a handful of breaking changes as the language team wrestles with past API design. The biggest change this time around is to the standard library Reader and Writer interfaces, which have been completely rearranged in the name of performance and reducing unneeded copies.

All existing std.io readers and writers are deprecated in favor of the newly provided std.Io.Reader and std.Io.Writer which are non-generic and have the buffer above the vtable - in other words the buffer is in the interface, not the implementation. This means that although Reader and Writer are no longer generic, they are still transparent to optimization; all of the interface functions have a concrete hot path operating on the buffer, and only make vtable calls when the buffer is full.

These changes are extremely breaking. I am sorry for that, but I have carefully examined the situation and acquired confidence that this is the direction that Zig needs to go. I hope you will strap in your seatbelt and come along for the ride; it will be worth it.