Struct libloading::Symbol

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

Symbol from a library.

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

The Deref trait implementation allows the use of Symbol as if it was a function or variable itself, without taking care to “extract” the function or variable manually most of the time.

Implementations

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

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

Extract the wrapped os::platform::Symbol.

Safety

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

Examples

unsafe {
    let lib = Library::new("/path/to/awesome.module").unwrap();
    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>, library: &'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 a reference to the library.

Safety

The library reference must be exactly the library sym was loaded from.

Examples

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

pub unsafe fn try_as_raw_ptr(self) -> Option<*mut c_void>

Try to convert the symbol into a raw pointer. Success depends on the platform. Currently, this fn always succeeds and returns some.

Safety

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

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

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

Lift Option out of the symbol.

Examples

unsafe {
    let lib = Library::new("/path/to/awesome.module").unwrap();
    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>