Rust 使用了函数“print”，但为什么它会警告我“未使用”？

这里是功能所在

如上所示，

wasm

模块将仅使用

wasm32 unknown

目标编译。而

打印

功能用于：

//huangjj27:env_loggersrc\fmt\writer\termcolor\shim_impl.rs:32-48
发布（在板条箱中：：fmt：：writer）fn打印（&self，buf:&Buffer）->io：：结果{
//此impl使用'eprint'和'print'宏
//而不是直接使用流。
//这是为了通过“货物测试”捕获它们的输出`
让log=String:：from_utf8_lossy（&buf.0）；
#[cfg（全部（target_arch=“wasm32”，target_vendor=“unknown”）]
wasm:：打印（&log，self.target）；
#[cfg（并非全部（target_arch=“wasm32”，target_vendor=“unknown”）]
匹配自我目标{
Target:：Stderr=>eprint！（“{}”，log），
目标：：Stdout=>print！（“{}”，log），
}
好（（））
}

然后我用以下方法进行测试：

wasm包测试--节点--无默认功能--测试节点

然后我得到了一个令人困惑的问题：

[INFO]: Checking for the Wasm target...
   Compiling env_logger v0.8.2 (C:\Users\huangjj27\Documents\codes\env_logger)
error: function is never used: `print`
   --> src\fmt\writer\wasm.rs:13:31
    |
13  | pub(in crate::fmt::writer) fn print(msg: &str, t: Target) {
    |                               ^^^^^
    |
note: lint level defined here
   --> src\lib.rs:280:54
    |
280 | #![deny(missing_debug_implementations, missing_docs, warnings)]
    |                                                      ^^^^^^^^
    = note: `#[deny(dead_code)]` implied by `#[deny(warnings)]`

error: function is never used: `print`
   --> src\fmt\writer\wasm.rs:13:31
    |
13  | pub(in crate::fmt::writer) fn print(msg: &str, t: Target) {
    |                               ^^^^^
    |
note: lint level defined here
   --> src\lib.rs:280:54
    |
280 | #![deny(missing_debug_implementations, missing_docs, warnings)]
    |                                                      ^^^^^^^^
    = note: `#[deny(dead_code)]` implied by `#[deny(warnings)]`

error: aborting due to previous error

error: could not compile `env_logger`.
warning: build failed, waiting for other jobs to finish...
error: aborting due to previous error

error: could not compile `env_logger`.

To learn more, run the command again with --verbose.
Error: Compilation of your program failed
Caused by: failed to execute `cargo build`: exited with exit code: 101
  full command: "cargo" "build" "--tests" "--target" "wasm32-unknown-unknown"

我的问题是：

为什么会出现警告，而我确实在某处使用了函数

wasm:：print

我该如何处理这个问题？解决或修复它是可以的（但我仍然需要保持lint配置处于启用状态）

---

如果您只在其他未使用的函数中使用某个函数，那么它仍然会向您发出警告。如果要禁用该函数的警告，可以将

#[allow（dead_code）]

放在函数标题前的行上。

我相信调用

wasm:：print

的函数也未使用。锈蚀会递归检查。哦，你正在向环境记录器添加wasm支持。我很困惑到底发生了什么。

[INFO]: Checking for the Wasm target...
   Compiling env_logger v0.8.2 (C:\Users\huangjj27\Documents\codes\env_logger)
error: function is never used: `print`
   --> src\fmt\writer\wasm.rs:13:31
    |
13  | pub(in crate::fmt::writer) fn print(msg: &str, t: Target) {
    |                               ^^^^^
    |
note: lint level defined here
   --> src\lib.rs:280:54
    |
280 | #![deny(missing_debug_implementations, missing_docs, warnings)]
    |                                                      ^^^^^^^^
    = note: `#[deny(dead_code)]` implied by `#[deny(warnings)]`

error: function is never used: `print`
   --> src\fmt\writer\wasm.rs:13:31
    |
13  | pub(in crate::fmt::writer) fn print(msg: &str, t: Target) {
    |                               ^^^^^
    |
note: lint level defined here
   --> src\lib.rs:280:54
    |
280 | #![deny(missing_debug_implementations, missing_docs, warnings)]
    |                                                      ^^^^^^^^
    = note: `#[deny(dead_code)]` implied by `#[deny(warnings)]`

error: aborting due to previous error

error: could not compile `env_logger`.
warning: build failed, waiting for other jobs to finish...
error: aborting due to previous error

error: could not compile `env_logger`.

To learn more, run the command again with --verbose.
Error: Compilation of your program failed
Caused by: failed to execute `cargo build`: exited with exit code: 101
  full command: "cargo" "build" "--tests" "--target" "wasm32-unknown-unknown"