Struct libloading::Symbol

pub struct Symbol<'lib, T: 'lib> { /* fields omitted */ }

Symbol from a library.

This type is a safeguard against using dynamically loaded symbols after a Library is unloaded. Primary method to create an instance of a Symbol is via Library::get.

Due to implementation of the Deref trait, an instance of Symbol may be used as if it was a function or variable directly, without taking care to “extract” function or variable manually most of the time.

See Library::get for details.

Methods

impl<'lib, T> Symbol<'lib, T>

pub unsafe fn into_raw(self) -> Symbol<T>

Extract the wrapped os::platform::Symbol.

Unsafety

Using this function relinquishes all the lifetime guarantees. It is up to programmer to ensure the resulting Symbol is not used past the lifetime of the Library this symbol was loaded from.

Examples

let lib = Library::new("/path/to/awesome.module").unwrap();
unsafe {
    let symbol: Symbol<*mut u32> = lib.get(b"symbol\0").unwrap();
    let symbol = symbol.into_raw();
}

pub unsafe fn from_raw<L>(sym: Symbol<T>, _: &'lib L) -> Symbol<'lib, T>

Wrap the os::platform::Symbol into this safe wrapper.

Note that, in order to create association between the symbol and the library this symbol came from, this function requires reference to the library provided.

Unsafety

It is invalid to provide a reference to any other value other than the library the sym was loaded from. Doing so invalidates any lifetime guarantees.

Examples

let lib = Library::new("/path/to/awesome.module").unwrap();
unsafe {
    let symbol: Symbol<*mut u32> = lib.get(b"symbol\0").unwrap();
    let symbol = symbol.into_raw();
    let symbol = Symbol::from_raw(symbol, &lib);
}

impl<'lib, T> Symbol<'lib, Option<T>>

pub fn lift_option(self) -> Option<Symbol<'lib, T>>

Lift Option out of the symbol.

Examples

let lib = Library::new("/path/to/awesome.module").unwrap();
unsafe {
    let symbol: Symbol<Option<*mut u32>> = lib.get(b"symbol\0").unwrap();
    let symbol: Symbol<*mut u32> = symbol.lift_option().expect("static is not null");
}

Trait Implementations

impl<'lib, T> Clone for Symbol<'lib, T>

fn clone(&self) -> Symbol<'lib, T>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'lib, T> Debug for Symbol<'lib, T>

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

Formats the value using the given formatter.

impl<'lib, T> Deref for Symbol<'lib, T>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &T

Dereferences the value.

impl<'lib, T: Send> Send for Symbol<'lib, T>

impl<'lib, T: Sync> Sync for Symbol<'lib, T>