连接整数变量的最惯用方式是什么？ [英] What is the most idiomatic way to concatenate integer variables?

问题描述

编译器似乎没有推断出整数变量是作为字符串文字传递给 concat！宏的，所以我发现了 stringify ！宏，将这些整数变量转换为字符串文字，但这看起来很难看：

The compiler doesn't seem to infer that the integer variables are passed as string literals into the concat! macro, so I found the stringify! macro that converts these integer variables into string literals, but this looks ugly:

fn date(year: u8, month: u8, day: u8) -> String
{
    concat!(stringify!(month), "/",
            stringify!(day), "/",
            stringify!(year)).to_string()
}

推荐答案

concat！接受文字并在 compile 时生成&'static str 。您应该使用格式！：

concat! takes literals and produces a &'static str at compile time. You should use format! for this:

fn date(year: u8, month: u8, day: u8) -> String {
    format!("{}/{}/{}", month, day, year)
}

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