Struct RbString 

#[repr(C)]
pub struct RbString {
    pub len: u32,
    pub data: *const u8,
}

FFI-safe borrowed string reference

This is a view into a UTF-8 string that the caller owns. The string data must remain valid for the duration of the FFI call.

Memory Layout

+--------+--------+
|  len   |  data  |
| (u32)  | (*u8)  |
+--------+--------+

Invariants

• If data is non-null, it must point to valid UTF-8 bytes
• If data is non-null, it must be null-terminated (for C compatibility)
• len is the byte length, NOT including the null terminator
• If len == 0 and data == null, the string is considered “not present” (None)
• If len == 0 and data != null, the string is an empty string

Fields

len: u32

Length in bytes (excluding null terminator)

data: *const u8

Pointer to null-terminated UTF-8 data

Implementations

impl RbString

pub const fn none() -> Self

Create an empty/absent string (represents None)

pub const fn from_static(s: &'static str) -> Self

Create a string from a static str

Safety

The string must be null-terminated. Use this only with string literals or strings known to have a null terminator.

pub fn is_present(&self) -> bool

Check if this string is present (not None)

pub fn is_empty(&self) -> bool

Check if this string is empty

pub unsafe fn as_str(&self) -> Option<&str>

Convert to a Rust string slice

Safety

• data must be valid for reads of len bytes
• data must point to valid UTF-8
• The memory must not be modified during the lifetime of the returned slice

pub unsafe fn to_string(&self) -> Option<String>

Convert to a Rust String (copies data)

Safety

Same requirements as as_str

Trait Implementations

impl Clone for RbString

fn clone(&self) -> RbString

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for RbString

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for RbString

fn default() -> Self

Returns the “default value” for a type.

impl Copy for RbString

impl Send for RbString

impl Sync for RbString