optional anyWriter as type of argument

[brazen stream]

i have:

pub fn myFunc(log: ?anytype) void {
    if (log) |l| l.writeAll("catched!");    
    ...... ...
}```

[trim monolith]

i assume your question is something like "why doesn't this work"?

you can't put any modifiers on anytype

if you want to require it to be optional, you can either do something like

pub fn myFunc(comptime LogType: type, log: ?LogType) void

or you can just use anytype and then inside the function use @typeInfo(@TypeOf(log)), check whether it is really optional, and use @compileError for a nice message if not

[brazen stream]

I sincerely don’t understand why there is a standard type for the allocator that can be specified, but not for the writer

i try use anytype and compiller write me error: expected optional type. those. when I send non-null to a function it is automatically non-optional

"comptime LogType: type" - It obviously doesn’t suit me because I use 2 different Writers. And sometimes I don’t want to send it to a function at all.

[pine valley]

The writer is comptime interface, the allocator is a runtime one

The runtime one is a single type since is just a vtable we pass around

While the comptime one is Generic over the error/write/read function

which mean one reader/writer is different than another one