BorshDeserialize 给出 try_from_slice 错误

Question

我正在研究 Rust 中的 "BorshDeserialize" 选项。并在使用特征边界时注意到以下问题。感谢任何帮助

示例代码

use borsh::{BorshDeserialize, BorshSerialize};
use solana_program::pubkey::Pubkey;
use std::mem;

#[derive(BorshSerialize, BorshDeserialize, PartialEq, Debug)]
struct SampleData<'a> {
    accounts: (&'a Pubkey, &'a Pubkey),
    data: String,
    timestamp: u64,
    owner: &'a Pubkey,
}

fn main() {
    println!(
        "Size of SampleData is {} bytes",
        mem::size_of::<SampleData>()
    );
    let _pub_key = Pubkey::default();
    let _a = SampleData {
        accounts: (&_pub_key, &_pub_key),
        data: "ABCDE".to_string(),
        timestamp: 1643116047,
        owner: &_pub_key,
    };
    let _encoded_a = _a.try_to_vec().unwrap();
    println!("{:?}", _encoded_a);
    let _decoded_a = SampleData::try_from_slice(&_encoded_a).unwrap();
    println!("decoded_a: {:?}", _decoded_a);
}

错误信息

error[E0599]: the function or associated item try_from_slice exists for struct SampleData<'_>, but its trait bounds were not satisfied
--> src/main.rs:27:34 | 6 | struct SampleData<'a> { | --------------------- | | | function or associated item try_from_slice not found for this | doesn't satisfy SampleData<'_>: BorshDeserialize ... 27 | let _decoded_a = SampleData::try_from_slice(&_encoded_a).unwrap(); |
^^^^^^^^^^^^^^ function or associated item cannot be called on SampleData<'_> due to unsatisfied trait bounds | note: the following trait bounds were not satisfied because of the requirements of the implementation of BorshDeserialize for _: (&Pubkey, &Pubkey): BorshDeserialize &Pubkey: BorshDeserialize --> src/main.rs:5:26 | 5 | #[derive(BorshSerialize, BorshDeserialize, PartialEq, Debug)] | ^^^^^^^^^^^^^^^^ 6 | struct SampleData<'a> { |
^^^^^^^^^^^^^^ = help: items from traits can only be used if the trait is implemented and in scope = note: the following trait defines an item try_from_slice, perhaps you need to implement it: candidate #1: BorshDeserialize = note: this error originates in the derive macro BorshDeserialize (in Nightly builds, run with -Z macro-backtrace for more info)

For more information about this error, try rustc --explain E0599. error: could not compile seralize due to previous error

Answer 1

问题是 SampleData 包含引用，这在正常的 Borsh 反序列化中不受支持。 Borsh 基于切片创建您的类型的新实例，但它无法创建引用。

如果你想坚持使用 Borsh，你应该将类型更改为：

#[derive(BorshSerialize, BorshDeserialize, PartialEq, Debug)]
struct SampleData {
    accounts: (Pubkey, Pubkey),
    data: String,
    timestamp: u64,
    owner: Pubkey,
}

BorshDeserialize 给出 try_from_slice 错误

BorshDeserialize gives try_from_slice error

rust

deserialization

solana