I'm curious about the reason for this limitation. I'm guessing it's a temporary restriction because I receive the error message "Subscripts cannot have noncopyable parameters yet" when using a noncopyable type. I tried searching for similar strings on GitHub to locate the source of the error message in the compiler, but couldn't find any. Can someone help me in understanding how to find the source in the compiler?
struct Foo {
subscript(foo: borrowing Foo) -> Foo { // 'borrowing' must not be used on subscript parameters
foo
}
}