如何将 dbg!() 重定向到标准输出?
How can I redirect dbg!() to stdout?
有些情况下 stderr 不可用。有没有办法让 dbg!()
打印到 stdout 或将与 dbg!()
相同的信息打印到 stdout 的替代命令?
对于替代命令,copy-and-paste implementation of dbg
,将 eprintln
更改为 println
并将 $crate
更改为 ::std
:
macro_rules! dbg {
// NOTE: We cannot use `concat!` to make a static string as a format argument
// of `println!` because `file!` could contain a `{` or
// `$val` expression could be a block (`{ .. }`), in which case the `println!`
// will be malformed.
() => {
::std::println!("[{}:{}]", ::std::file!(), ::std::line!())
};
($val:expr $(,)?) => {
// Use of `match` here is intentional because it affects the lifetimes
// of temporaries -
match $val {
tmp => {
::std::println!("[{}:{}] {} = {:#?}",
::std::file!(), ::std::line!(), ::std::stringify!($val), &tmp);
tmp
}
}
};
($($val:expr),+ $(,)?) => {
($(::std::dbg!($val)),+,)
};
}
fn main() {
dbg!(1 + 1);
}
有些情况下 stderr 不可用。有没有办法让 dbg!()
打印到 stdout 或将与 dbg!()
相同的信息打印到 stdout 的替代命令?
对于替代命令,copy-and-paste implementation of dbg
,将 eprintln
更改为 println
并将 $crate
更改为 ::std
:
macro_rules! dbg {
// NOTE: We cannot use `concat!` to make a static string as a format argument
// of `println!` because `file!` could contain a `{` or
// `$val` expression could be a block (`{ .. }`), in which case the `println!`
// will be malformed.
() => {
::std::println!("[{}:{}]", ::std::file!(), ::std::line!())
};
($val:expr $(,)?) => {
// Use of `match` here is intentional because it affects the lifetimes
// of temporaries -
match $val {
tmp => {
::std::println!("[{}:{}] {} = {:#?}",
::std::file!(), ::std::line!(), ::std::stringify!($val), &tmp);
tmp
}
}
};
($($val:expr),+ $(,)?) => {
($(::std::dbg!($val)),+,)
};
}
fn main() {
dbg!(1 + 1);
}