rustのワーニング help: consider prefixing with an underscore:
fn main() { let n1 = 10_000; let n2 = 0u8; let n3 = -100_isize; let n4 = 10; let n5 = n3 + n4; }
help: consider prefixing with an underscore: _n1
のワーニングがでる。
PS > cargo run --example "ch04_03_integer" warning: file found to be present in multiple build targets: \rustbook\ch04\ex04\examples\ch04_01_units.rs Compiling ex04 v0.1.0 (rustbook\ch04\ex04) warning: unused variable: `n1` --> examples\ch04_03_integer.rs:2:9 | 2 | let n1 = 10_000; | ^^ help: consider prefixing with an underscore: `_n1` | = note: `#[warn(unused_variables)]` on by default warning: unused variable: `n2` --> examples\ch04_03_integer.rs:3:9 | 3 | let n2 = 0u8; | ^^ help: consider prefixing with an underscore: `_n2` warning: unused variable: `n5` --> examples\ch04_03_integer.rs:7:9 | 7 | let n5 = n3 + n4; | ^^ help: consider prefixing with an underscore: `_n5` Finished dev [unoptimized + debuginfo] target(s) in 1.15s Running `target\debug\examples\ch04_03_integer.exe`
アンダーバーを変数の前につけると、ワーニングは消えた。
fn main() { let _n1 = 10_000; let _n2 = 0u8; let _n3 = -100_isize; let _n4 = 10; let _n5 = _n3 + _n4; }
使用している、rustの教科書。
- 作者: κeen,河野達也,小松礼人
- 出版社/メーカー: 技術評論社
- 発売日: 2019/05/08
- メディア: 単行本(ソフトカバー)
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