我想在两种不同类型的对象上使用write_fmt
方法:
use std::fmt::Write;
use std::io::Write;
fn main() {
let mut a = String::new();
let mut b = std::fs::File::create("test").unwrap();
a.write_fmt(format_args!("hello"));
b.write_fmt(format_args!("hello"));
}
我在使用Write
时出错,因为它们的名称相同:
error[E0252]: a trait named `Write` has already been imported in this module
--> src/main.rs:8:5
|
7 | use std::fmt::Write;
| --------------- previous import of `Write` here
8 | use std::io::Write;
| ^^^^^^^^^^^^^^ `Write` already imported
a.write_fmt(format_args!("hello"));
b.write_fmt(format_args!("hello"));
或者我得到一个错误,说这个特征不可用:
error[E0599]: no method named `write_fmt` found for type `std::fs::File` in the current scope
--> src/main.rs:76:4
|
76 | b.write_fmt(format_args!("hello"));
| ^^^^^^^^^
|
= help: items from traits can only be used if the trait is in scope; the following trait is implemented but not in scope, perhaps add a `use` for it:
= help: candidate #1: `use std::io::Write;`