普通のvectorから1つだけ削除
let target = 2;
let mut vec = vec![1, 2, 3, 4, 5];
if let Some(remove_index) = vec.iter().position(|x| *x == target){
vec.remove(remove_index);
}
println!("{:?}", vec);
[1, 3, 4, 5]
vectorから複数削除する
let targets = [2, 4];
let mut vec = vec![1, 2, 3, 4, 5];
for target in targets {
if let Some(remove_index) = vec.iter().position(|x| *x == target){
vec.remove(remove_index);
}
}
println!("{:?}", vec);
[1, 3, 5]
vectorの中身が構造体の時
=> 基本同じ処理
#[derive(Serialize, Deserialize, Clone, Debug, PartialEq)]
struct Person {
last: String,
first: String,
age: i32
}
//
let mut vec: Vec<Person> = Vec::new();
let person1 = Person{last:"yamada".to_string(), first:"taro".to_string(), age: 20};
let person2 = Person{last:"yoshida".to_string(), first:"akira".to_string(), age: 15};
let person3 = Person{last:"takahashi".to_string(), first:"kazumi".to_string(), age: 21};
let person4 = Person{last:"ichiba".to_string(), first:"kumi".to_string(), age: 22};
let person5 = Person{last:"okamoto".to_string(), first:"hajime".to_string(), age: 17};
vec.push(person1.clone());
vec.push(person2.clone());
vec.push(person3.clone());
vec.push(person4.clone());
vec.push(person5.clone());
let mut engineers:Vec<Person> = Vec::new();
engineers.push(person1);
engineers.push(person2);
for engineer in engineers {
if let Some(remove_index) = vec.iter().position(|x| *x == engineer){
vec.remove(remove_index);
}
}
println!("{:?}", vec);
[Person { last: “takahashi”, first: “kazumi”, age: 21 }, Person { last: “ichiba”, first: “kumi”, age: 22 }, Person { last: “okamoto”, first: “hajime”, age: 17 }]
### mutexのvectorの場合
=> うまくいかない
static VECT: Lazy<Mutex<Vec<Person>>> = Lazy::new(|| Mutex::new(vec![]));
#[tokio::main]
async fn main() {
let mut vec: Vec<Person> = Vec::new();
let person1 = Person{last:"yamada".to_string(), first:"taro".to_string(), age: 20};
let person2 = Person{last:"yoshida".to_string(), first:"akira".to_string(), age: 15};
let person3 = Person{last:"takahashi".to_string(), first:"kazumi".to_string(), age: 21};
let person4 = Person{last:"ichiba".to_string(), first:"kumi".to_string(), age: 22};
let person5 = Person{last:"okamoto".to_string(), first:"hajime".to_string(), age: 17};
VECT.lock().unwrap().push(person1.clone());
VECT.lock().unwrap().push(person2.clone());
VECT.lock().unwrap().push(person3.clone());
VECT.lock().unwrap().push(person4.clone());
VECT.lock().unwrap().push(person5.clone());
let mut engineers:Vec<Person> = Vec::new();
engineers.push(person1);
engineers.push(person2);
for engineer in engineers {
if let Some(remove_index) = VECT.lock().unwrap().iter().position(|x| *x == engineer){
VECT.lock().unwrap().remove(remove_index);
}
}
println!("{:?}", VECT.lock().unwrap());
}
Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.94s
Running `target/debug/app`
処理が止まったままになる…
ちょっとコードが冗長になるが、別の関数に切り出して、削除後のデータを再度空にしたmutexに入れるという処理を行うと上手くいく。
#[tokio::main]
async fn main() {
// mutex vectorの準備
let mut vec: Vec<Person> = Vec::new();
let person1 = Person{last:"yamada".to_string(), first:"taro".to_string(), age: 20};
let person2 = Person{last:"yoshida".to_string(), first:"akira".to_string(), age: 15};
let person3 = Person{last:"takahashi".to_string(), first:"kazumi".to_string(), age: 21};
let person4 = Person{last:"ichiba".to_string(), first:"kumi".to_string(), age: 22};
let person5 = Person{last:"okamoto".to_string(), first:"hajime".to_string(), age: 17};
VECT.lock().unwrap().push(person1.clone());
VECT.lock().unwrap().push(person2.clone());
VECT.lock().unwrap().push(person3.clone());
VECT.lock().unwrap().push(person4.clone());
VECT.lock().unwrap().push(person5.clone());
println!("{:?}", VECT.lock().unwrap());
// mutex vectorから削除したい値
let mut engineers:Vec<Person> = Vec::new();
engineers.push(person1);
engineers.push(person2);
let objs = processing_mutex_vector(engineers).await;
// 一度全て削除し、残したいデータを挿入する
VECT.lock().unwrap().clear();
for obj in objs {
VECT.lock().unwrap().push(obj);
}
println!("{:?}", VECT.lock().unwrap());
}
async fn processing_mutex_vector(engineers:Vec<Person>) -> Vec<Person> {
let mut binding = VECT.lock().unwrap();
let objs = binding.deref_mut();
for engineer in engineers {
if let Some(remove_index) = objs.iter().position(|x| *x == engineer){
objs.remove(remove_index);
}
}
return objs.to_vec();
}
[Person { last: “yamada”, first: “taro”, age: 20 }, Person { last: “yoshida”, first: “akira”, age: 15 }, Person { last: “takahashi”, first: “kazumi”, age: 21 }, Person { last: “ichiba”, first: “kumi”, age: 22 }, Person { last: “okamoto”, first: “hajime”, age: 17 }]
[Person { last: “takahashi”, first: “kazumi”, age: 21 }, Person { last: “ichiba”, first: “kumi”, age: 22 }, Person { last: “okamoto”, first: “hajime”, age: 17 }]
