resources

此包提供 Resources 结构体：一个容器，最多存储每种类型的单个值，并允许安全地、并发地访问任何一个值，同时不违反借用规则。

它旨在用作存储与 ECS（实体组件系统）中任何特定实体不相关联的数据的存储实现，但仍需要系统并发访问。

Cargo 功能

• fetch - 当启用时，公开 Resources::fetch()，允许用一行代码检索最多 16 个资源。

示例

use resources::*;

struct SomeNumber(usize);

struct SomeString(&'static str);

fn main() {
    let mut resources = Resources::new();
    resources.insert(SomeNumber(4));
    resources.insert(SomeString("Hello!"));
    let resources = resources;  // This shadows the mutable binding with an immutable one.

    {
        let mut some_number = resources.get_mut::<SomeNumber>().unwrap();
        let mut some_string = resources.get_mut::<SomeString>().unwrap();

        // Immutably borrowing a resource that's already borrowed mutably is not allowed.
        assert!(resources.get::<SomeNumber>().is_err());

        some_number.0 = 2;
        some_string.0 = "Bye!";
    }

    // The mutable borrows now went out of scope, so it's okay to borrow again however needed.
    assert_eq!(resources.get::<SomeNumber>().unwrap().0, 2);

    // Multiple immutable borrows are okay.
    let some_string1 = resources.get::<SomeString>().unwrap();
    let some_string2 = resources.get::<SomeString>().unwrap();
    assert_eq!(some_string1.0, some_string2.0);
}