rust - 如何在Rust中将变量作为字符串文字传递？

Question

我正在使用仅接受字符串文字的宏 hex! 。
我有一个从函数返回的值，并存储在变量中。我无法对值进行硬编码并调用此函数。那么，如何使用变量调用hex!宏？

这是我的工作代码:

let account: AccountId32 = hex_literal::hex!["d43593c715fdd31c61141abd04a99fd6822c8558854ccde39a5684e7a56da27d"].into();

这是我面临错误的代码:

let account_id = "d43593c715fdd31c61141abd04a99fd6822c8558854ccde39a5684e7a56da27d";
let account: AccountId32 = hex_literal::hex!(&account_id).into();

错误是:

error: proc-macro derive panicked
  --> src/examples/example_substratekitties.rs:49:32
   |
49 |     let account: AccountId32 = hex_literal::hex!(&account_id).into();
   |                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: message: expected one string literal
   = note: this warning originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)

hex!宏的所有示例仅使用字符串文字进行演示。

Answer 1

你不能。这实际上是不可能的。文字是在程序源代码中逐字写入值的东西。

不要使用该宏，因为它不会执行您想要的操作(强调我的意思):

This crate provides hex! macro for converting hexadecimal string literal to byte array at compile time.

也许您想要 hex crate？

也可以看看:

What is the difference between literals and non-literals, other than the fact that non-literals go into the heap?

What does the word "literal" mean?

How can I convert a hex string to a u8 slice?

Converting a hexadecimal string to a decimal integer

Decimal number to hexadecimal string

How to convert hex string to a float in Rust?

How do I convert a string to hex in Rust?

Show u8 slice in hex representation