# What's new in F# 4.6

F# 4.6 adds multiple improvements to the F# language.

## Get started

F# 4.6 is available in all .NET Core distributions and Visual Studio tooling. Get started with F# to learn more.

## Anonymous records

Anonymous records are a new kind of F# type introduced in F# 4.6. They are simple aggregates of named values that don't need to be declared before use. You can declare them as either structs or reference types. They're reference types by default.

```
open System
let getCircleStats radius =
let d = radius * 2.0
let a = Math.PI * (radius ** 2.0)
let c = 2.0 * Math.PI * radius
{| Diameter = d; Area = a; Circumference = c |}
let r = 2.0
let stats = getCircleStats r
printfn "Circle with radius: %f has diameter %f, area %f, and circumference %f"
r stats.Diameter stats.Area stats.Circumference
```

They can also be declared as structs for when you want to group value types and are operating in performance-sensitive scenarios:

```
open System
let getCircleStats radius =
let d = radius * 2.0
let a = Math.PI * (radius ** 2.0)
let c = 2.0 * Math.PI * radius
struct {| Diameter = d; Area = a; Circumference = c |}
let r = 2.0
let stats = getCircleStats r
printfn "Circle with radius: %f has diameter %f, area %f, and circumference %f"
r stats.Diameter stats.Area stats.Circumference
```

They're quite powerful and can be used in numerous scenarios. Learn more at Anonymous records.

## ValueOption functions

The ValueOption type added in F# 4.5 now has "module-bound function parity" with the Option type. Some of the more commonly-used examples are as follows:

```
// Multiply a value option by 2 if it has value
let xOpt = ValueSome 99
let result = xOpt |> ValueOption.map (fun v -> v * 2)
// Reverse a string if it exists
let strOpt = ValueSome "Mirror image"
let reverse (str: string) =
match str with
| null
| "" -> ValueNone
| s ->
str.ToCharArray()
|> Array.rev
|> string
|> ValueSome
let reversedString = strOpt |> ValueOption.bind reverse
```

This allows for ValueOption to be used just like Option in scenarios where having a value type improves performance.

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