Improving C# Memory Safety

(devblogs.microsoft.com)

85 points | by soheilpro 1 day ago

3 comments

  • superjan 3 hours ago
    What you can do in C# today is convert any unsafe pointer to Span whenever you get your hands on it, and pass around slices. You can still drop down to ‘fixed’ when it turns out you need it for performance.
  • pjmlp 1 day ago
    Most likely a side effect related to Windows team finally giving some C# love, instead of COM and C++, given the comparisons between C# 16 with Rust and Swift in a few article sections.
    • moomin 3 hours ago
      The Windows team is talking to DevDiv again? Satan's putting on his ice skates right now.
      • pjmlp 2 hours ago
        One can only hope.

        C++/WinRT is in maintenance, and you will notice the WinUI 3.0 does most of their demos, and gallery with C#.

  • SideburnsOfDoom 1 hour ago
    > The unsafe keyword is being redesigned

    OK, I see a lot of C# code often and over a long time.

    I see the "unsafe" keyword used approximately never.

    I'm sure that this is useful for some cases. But not everyday things for most of us. If we did use it, it would be carefully isolated in a library for a specific purpose.

    • tialaramex 53 minutes ago
      This moves C# to a more modern systematic understanding of what this keyword is for, but it'll remain very rare in C# the same way it's rare in Rust, and presumably in Swift.

      The choice of keyword "unsafe" is partly psychological. Turns out if you called this exact same feature "trusted" or whatever the programmers don't have the appropriate feelings about it. They want to write trusted code, they don't want to write unsafe code, so making them write the keyword "unsafe" provides that psychological disincentive.

    • zmj 14 minutes ago
      There are standard library APIs that let you do memory-unsafe things without the unsafe keyword (CollectionsMarshal, MemoryMarshal). They're useful, but the burden is on the caller to uphold the invariants. This proposal seems aimed at making that kind of contract more explicit and obvious.
    • pjmlp 1 hour ago
      Many of us use it in scenarios where others would write a blog post about a rewrite in Rust, C++ or whatever.

      CLR was designed to support languages like C++, yet many don't learn the knobs.

    • Quothling 25 minutes ago
      Around here C# is only really used at stagnant middle sized companies with horrible code bases. The sort where the company follow Uncle Bob religiously, while completely misunderstanding everything Uncle Bob ever said. Doesn't mean the language (and it's runtime) can't be good.
    • smt88 27 minutes ago
      C# is like Rust in the sense that a regular (web, desktop, etc.) developer probably won’t need unsafe, but it’s useful for lower-level work in libraries and CLI tools, especially where performance is important.