Safety Guarantees

When we say NextStd is “safe,” we aren’t just talking about compiler warnings or best practices. We are talking about architectural guarantees enforced at the Foreign Function Interface (FFI) boundary between C and Rust.

Here are the core vulnerability classes that NextStd entirely eliminates from your C codebase.

1. Null Pointer Immunity (No More Segfaults)

In standard C, passing a NULL pointer to strlen() or strcpy() results in immediate Undefined Behavior, typically manifesting as a fatal Segmentation Fault.

NextStd actively intercepts bad memory. Every single FFI boundary function in the library checks for NULL before performing any operations. If a NULL pointer is detected, the operation is safely aborted, and an NS_ERROR_ANY code is returned for your NS_TRY block to catch gracefully.

2. Out-of-Memory (OOM) Protection

Standard C’s malloc returns NULL when the heap is exhausted—a condition developers frequently forget to check. Standard Rust, on the other hand, will panic and instantly crash the program when an allocation fails.

NextStd takes the safe middle path. It uses Rust’s try_reserve API for all dynamic heap allocations. If the system runs out of memory (a critical threat in embedded and constrained environments), NextStd safely catches the failure and returns an NS_ERROR_STRING_ALLOC code without crashing your process.

3. Buffer Overflow Prevention

C strings are notoriously dangerous null-terminated (\0) arrays. If you forget the terminator, or use strcat into a buffer that is even one byte too small, you silently overwrite adjacent memory.

NextStd uses a length-prefixed struct combined with Small String Optimization (SSO). The exact length of the string is always known. If a string needs to grow beyond its 24-byte inline capacity, NextStd automatically and safely requests exactly the right amount of heap memory. Buffer overflows are mathematically impossible by design.

4. Format String Vulnerabilities

Using printf("%d", "text") forces the C compiler to trust the developer blindly. If the format specifier doesn’t match the variable type, the program reads garbage memory from the stack or crashes entirely.

NextStd leverages C11 _Generic macros to completely eliminate this class of bugs by routing types at compile time:

int age = 21;
ns_string name; // Assume initialized

ns_println(age);  // Automatically routes to ns_print_int
ns_println(name); // Automatically routes to ns_print_string

Because there are no format strings, format string vulnerabilities simply cannot exist.