Rust by default will not allow you to make certain kinds of errora, which is great. But if you are doing something advanced, down at the hardware level [see below], you might need to disable those defaults in order to write the code you need. This is what people mean by “unsafe” – lacking the normal memory safeguards.
With careful coding, “unsafe rust” or normal C, for that matter, can be free of bugs and safe. But if programmers make a mistake, vulnerabilities can creep in more easily in the unsafe sections.
But if you are doing something advanced, down at the hardware level
This part is wrong. Otherwise yes correct.
The “unsafe” code in rust is allowed to access memory locations in ways that skip the compiler’s check and guarantee that that memory location has valid data. They programmer is on their own to ensure that.
Which as you say is just the normal state of affairs for all C code.
This is needed not because of hardware access but just because sometimes the proof that the access is safe is beyond what the compiler is able to represent.
Thank you for the correction, I’ll edit my comment.
sometimes the proof that the access is
safe is bevond what the compiler is able to represent
Could you say a few more words about this? In what situations do you have to write ‘unsafe-tagged’ code blocks? Could this be changed by improvements to the compiler? Or is it necessitated by the type of task being done by the code?
Rust by default will not allow you to make certain kinds of errora, which is great. But if you are doing something advanced,
down at the hardware level[see below], you might need to disable those defaults in order to write the code you need. This is what people mean by “unsafe” – lacking the normal memory safeguards.With careful coding, “unsafe rust” or normal C, for that matter, can be free of bugs and safe. But if programmers make a mistake, vulnerabilities can creep in more easily in the unsafe sections.
Is that basically it?
This part is wrong. Otherwise yes correct.
The “unsafe” code in rust is allowed to access memory locations in ways that skip the compiler’s check and guarantee that that memory location has valid data. They programmer is on their own to ensure that.
Which as you say is just the normal state of affairs for all C code.
This is needed not because of hardware access but just because sometimes the proof that the access is safe is beyond what the compiler is able to represent.
Thank you for the correction, I’ll edit my comment.
Could you say a few more words about this? In what situations do you have to write ‘unsafe-tagged’ code blocks? Could this be changed by improvements to the compiler? Or is it necessitated by the type of task being done by the code?