Given:
format!("{red}{}{reset}", "text", red = "RED", blue = "BLUE", reset = "RESET");
编译器退出并出现错误:
error: named argument never used
--> example.rs:1:47
|
1 | format!("{red}{}{reset}", "text", red = "RED", blue = "BLUE", reset = "RESET");
| ^^^^^^^^^^^^^
通常,这不会成为问题,因为blue
应该删除,但我的用例是一个包装宏(简化):
macro_rules! log {
($fmt:expr, $($arg:tt)*) => {
println!($fmt, $($arg)*, blue = "BLUE", red = "RED", reset = "RESET");
};
}
有时,它像这样使用(简化),但有时使用不同的颜色,你会明白要点:
log!("{red}{}{reset}", "text");
编译器退出并出现类似错误:
error: named argument never used
--> example.rs:3:26
|
3 | println!($fmt, $($arg)*, blue = "BLUE", red = "RED", reset = "RESET");
| ^^^^^^^^^^^^^
是否有可能只是ignore未使用的参数,而不是在它们上出错?