Function ffi_string_owned 

pub unsafe fn ffi_string_owned<F>(ffi_call: F) -> Option<String>
where
    F: FnOnce() -> *mut i8,

Retrieves a string from an FFI function that returns an owned C string pointer.

This is more efficient than buffer-based retrieval as it avoids pre-allocation. The FFI function allocates the string (via strdup) and this function takes ownership and frees it.

Arguments

• ffi_call - A closure that returns an owned C string pointer (or null)

Returns

• Some(String) if the pointer was non-null and valid UTF-8
• None if the pointer was null

Safety

The caller must ensure the returned pointer was allocated by Swift’s strdup or equivalent, and that sc_free_string properly frees it.