Struct libloading::Symbol

source ·
pub struct Symbol<'lib, T: 'lib> { /* private fields */ }
Available on Unix or Windows only.
Expand description

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

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();
}

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);
}

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

Returns a copy of the value. Read more
Performs copy-assignment from source. Read more
Formats the value using the given formatter. Read more
The resulting type after dereferencing.
Dereferences the value.

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
Uses borrowed data to replace owned data, usually by cloning. Read more
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.