Sometimes for efficiency, you may want to write low-level code that can potentially corrupt memory or be vulnerable to security exploits. V supports writing such code, but not by default.
V requires that any potentially memory-unsafe operations are marked intentionally. Marking them also indicates to anyone reading the code that there could be memory-safety violations if there was a mistake.
Examples of potentially memory-unsafe operations are:
- Pointer arithmetic
- Pointer indexing
- Conversion to a pointer from an incompatible type
- Calling certain C functions, e.g.
To mark potentially memory-unsafe operations, enclose them in an
Best practice is to avoid putting memory-safe expressions inside an
so that the reason for using
unsafe is as clear as possible.
Generally any code you think is memory-safe should not be inside an
so the compiler can verify it.
If you suspect your program does violate memory-safety, you have a head start on
finding the cause: look at the
unsafe blocks (and how they interact with