format_args_nl Macrocore::format_args_nl source· macro_rules!format_args_nl { ($fmt:expr) => { ... }; ($fmt:expr, $($args:tt)*) => { ... }; } 🔬This is a nightly-only experimental API. (format_args_nl) 与format_args相同,但最后添加了一个换行符。
= note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more inf...
| = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info) help: consider cloning the value if the performance cost is acceptable | 21 | let s2 = s1.clo...
("b: {b}"); | ^ `b` used here but it is possibly-uninitialized | = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info) error: aborting due to ...
= note: this error originatesinthe macro `$crate::format_args_nl` (inNightly builds, run with -Z macro-backtraceformore info) For more information about this error, try `rustc --explain E0382`. 左右滑动查看完整代码 由于Rust在let s2 = s1操作执行之后将s1的内存所有权转移给了s2,因此它认为...
("rect1 is {rect1:?}");|^^^`Rectangle`cannot be formatted using`{:?}`|=help: the trait`Debug`is not implementedfor`Rectangle`=note:add`#[derive(Debug)]`to`Rectangle`or manually`impl DebugforRectangle`=note: this error originatesinthe macro`$crate::format_args_nl`whichcomes from the...
宏,但是expand确是 format_args 宏。大概可能是因为文档中说format_args_nl宏是nightly模式下的吧!并没有完全展开是因为该宏是内置宏(rustc_builtin_macro)。 在使用声明宏时,我们需要为参数明确类型,刚才的例子都是使用的expr,其实还可以使用下面这些: item,比如一个函数、结构体、模块等。 block,代码块。比如...
{ | --- ^^^ this parameter takes ownership of the value | | | in this function = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info) help: consider...
= note: this error originates in the macro `$crate::format_args_nl` (in Nightly builds, run with -Z macro-backtrace for more info) For more information about this error, try `rustc --explain E0382`. 1. 2. 3. 4. 5. 6.
("{}", s1);// | ^^ value borrowed here after move// |// = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)// help: consider clon...