IS4

`MatchFailure`/`MatchSkip` patterns

3

**I propose we** have a clean way of suppressing FS0025 (Incomplete pattern matches on this expression.) by making it explicit what action should happen. ### `MatchFailure` ```fs let inline (|MatchFailure|)...

**I propose we** are allowed to use the currently internal `byref` type as synonymous to one of the normal byref types `byref`, `outref

when 'T : default

4

**I propose we** have a constraint of the form type-parameter : default to restrict the parameter only to types that support zero-initialization, exactly as demanded by [`DefaultValue`](https://fsharp.github.io/fsharp-core-docs/reference/fsharp-core-defaultvalueattribute.html). In addition, certain...

Constant expressions in patterns

9

**I propose we** have a way to embed arbitrary constant expressions in patterns, such as via the following syntax: ```fs match x | 1 -> () // a single literal,...

Property references

10

**I propose we** have the possibility to use the `&` operator to get the "reference" to a normal property (or indexer), to be able to bind a property to a...

Allow mutating structs through read-only property setters in non-mutable contexts

7

**I propose we** allow the mutation (via `, index: int) = member this.Value with get() = list[index] and set v = list[index]