> For the complete documentation index, see [llms.txt](https://demystifyfp.gitbook.io/fstoolkit-errorhandling/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://demystifyfp.gitbook.io/fstoolkit-errorhandling/fstoolkit.errorhandling/taskresultoption/map3.md).

# map3

### TaskResultOption.map3

Namespace: `FsToolkit.ErrorHandling`

Function Signature:

```fsharp
('a -> 'b -> 'c -> 'd)
  -> Task<Result<'a option, 'e>>
  -> Task<Result<'b option, 'e>> 
  -> Task<Result<'c option, 'e>>
  -> Task<Result<'d option, 'e>>
```

### Examples

Note: Many use-cases requiring `map` operations can also be solved using [the `taskResultOption` computation expression](/fstoolkit-errorhandling/fstoolkit.errorhandling/taskresultoption/ce.md).