Example
fn name() void {}
fn name() !void {}```#what's the meaning and use case of void and !void
light marlin
tidal tapir
void means it returns nothing
!void means it returns either nothing, or an error from an inferred error union (zig looks at which errors your function can actually return)
light marlin
So more like the any for zig?
tidal tapir
for instance, allocators return error.OutOfMemory when they fail, so if your function calls try allocator.alloc(whatever), zig notices that it could return that error so its return type is essentially error{OutOfMemory}!void
tidal tapir
So more like the any for zig?
sorta
there is also an anyerror keyword which is different... idk when you need that in practice
maybe for function pointers?
anyerror means "can return any error". omitting the error union means "can return any error from a finite set, but i don't want to write out that finite set"
light marlin
Ok thanks i understand it now
tidal tapir
:D
light marlin
Is it a must i put it when a fn is not returning something ?
tidal tapir
you can't omit the return type, you need to write void explicitly
light marlin
Because it look like a type definition
tidal tapir
void means "returns nothing"
!void means "returns nothing or an error"
same for other types btw, you can have for instance !u32 for "error or a u32"
light marlin
you can't omit the return type, you need to write `void` explicitly
At the start of the function?
void fn name() {} ?
tidal tapir
Example
```
fn name() void {}
```
```
fn name() !void {}```
no, like you have it here
fn name() void {}
light marlin
But it's more like inferring the type?
tidal tapir
void doesn't do any inference
!void means the set of errors that can be returned by your function is inferred
only the errors returned by a function can be inferred, the return type itself has to be written explicitly
light marlin
Ok thanks