'static lifetime not inferred in const context

[grantslatton]

I tried this code:

struct Foo;

impl Foo {
    const ALL_METHODS: &[(&str, fn(&Self) -> usize)] = &[("foo", Self::foo)];
    
    fn foo(&self) -> usize {
        123
    }
}

I expected to see this happen: successful compile

Instead, this happened:

error[[E0491]](https://doc.rust-lang.org/stable/error_codes/E0491.html): in type `&[(&str, for<'a> fn(&'a Foo) -> usize)]`, reference has a longer lifetime than the data it references
 --> src/lib.rs:5:5
  |
5 |     const ALL_METHODS: &[(&str, fn(&Self) -> usize)] = &[("foo", Self::foo)];
  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
note: the pointer is valid for the anonymous lifetime as defined here
 --> src/lib.rs:5:24
  |
5 |     const ALL_METHODS: &[(&str, fn(&Self) -> usize)] = &[("foo", Self::foo)];
  |                        ^
note: but the referenced data is only valid for the anonymous lifetime as defined here
 --> src/lib.rs:5:24
  |
5 |     const ALL_METHODS: &[(&str, fn(&Self) -> usize)] = &[("foo", Self::foo)];
  |

Adding some 'statics fixes it, but I think these are supposed to be unnecessary now:

const ALL_METHODS: &'static [(&'static str, fn(&Self) -> usize)] = &[("foo", Self::foo)]

[compiler-errors]

Minimized:

struct Foo;

impl Foo {
    const CONST: &[&str] = &["foo"];
}

fn main() {}

[fmease]

Note that this works as intended. A PR for fail→pass would need to be t-lang fcp'ed.

[compiler-errors]

This is inadvertently introducing early-bound lifetimes for elided lifetimes in associated const params -- that is:

impl Foo {
  const CONST: &str = "";
}

Is desugaring to:

impl<'a> Foo<'a> {
  const CONST: &'a str = "";
}

I don't consider this correct behavior.

[compiler-errors]

Though I do agree with your assessment @fmease, a PR to make this code pass would require at least a T-lang FCP. I will probably not do that given the opinion stated in the comment you linked.