当我实现自定义错误类型时,我收到了以下错误:
the trait bound `std::io::Error: std::clone::Clone` is not satisfied
这是我的自定义错误枚举:
use std::fmt;
use std::io;
use crate::memtable::Memtable;
// Define our error types. These may be customized for our error handling cases.
// Now we will be able to write our own errors, defer to an underlying error
// implementation, or do something in between.
#[derive(Debug, Clone)]
pub enum MemtableError {
Io(io::Error),
FromUTF8(std::string::FromUtf8Error),
NotFound,
}
// Generation of an error is completely separate from how it is displayed.
// There's no need to be concerned about cluttering complex logic with the display style.
//
// Note that we don't store any extra info about the errors. This means we can't state
// which string failed to parse without modifying our types to carry that information.
impl fmt::Display for MemtableError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "Some error occurred!");
Ok(())
}
}
// a test function that returns our error result
fn raises_my_error(memtable: Memtable, key: String) -> Result<(),MemtableError> {
match memtable.read(key) {
Ok(v) => Ok(()),
Err(e) => Err(e),
}
}
我做错了什么?我尝试跟随这些示例: