Struct SetCallbackError 

pub struct SetCallbackError(/* private fields */);

Error returned when installing a process-global callback whose slot is already occupied.

Each callback slot in crate::core::callbacks (set_save_file_data_callback, set_load_file_data_callback, set_save_file_text_callback, set_load_file_text_callback) holds at most one function at a time. Calling a setter while its slot is occupied returns this error rather than silently overwriting. The inner &'static str names which callback kind was already set (e.g. "save file data").

Cause: A previous call to the same setter installed a callback that has not been removed.

Recovery: Keep a single registration site per callback kind, or remove the existing callback (where an unset function exists) before installing a new one.

Examples

use raylib::prelude::*;
use raylib::core::callbacks::set_save_file_data_callback;

fn writer(_path: &str, _bytes: &[u8]) -> bool { true }
set_save_file_data_callback(writer).expect("first install");
match set_save_file_data_callback(writer) {
    Err(e) => eprintln!("{e}"), // "there is a save file data callback already set"
    Ok(()) => unreachable!(),
}

Trait Implementations

impl Debug for SetCallbackError

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

Formats the value using the given formatter.

impl Display for SetCallbackError

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

Formats the value using the given formatter.

impl Error for SetCallbackError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<SetCallbackError> for RaylibError

fn from(source: SetCallbackError) -> Self

Converts to this type from the input type.