memory - 为什么在Rust中 “capture by reference”与 “capture a reference by value”等效？

Question

摘自Huon Wilson的Finding Closure in Rust:

Capturing entirely by value is also strictly more general than capturing by reference: the reference types are first-class in Rust, so "capture by reference" is the same as "capture a reference by value". Thus, unlike C++, there’s little fundamental distinction between capture by reference and by value, and the analysis Rust does is not actually necessary: it just makes programmers’ lives easier.

我竭尽全力解决这个问题。如果捕获“按值”引用，是否捕获了存储在堆中的数据？还是引用了在堆栈上找到的引用的指针值？

Answer 1

Or does it refer to the pointer value of the reference, which is found on the stack?

是的，ish。
在Rust中，引用是经过规范化的，它们是您实际操作的东西。因此，当您按值捕获引用时，您捕获的是引用本身(指针，这实际上是Rust引用)，而不是引用者(指针)。
按引用捕获基本上只是隐式创建一个引用并按值捕获它。