Cannot find impl of trait with literal &'static str const parameter

[rodrimati1992]

This code ran in the latest nightly(2019-11-19) in the playground does not compile:

#![feature(const_generics)]

trait FieldType<const NAME: &'static str> {
    type FieldType;
}

impl<T> FieldType<"0"> for (T,) {
    type FieldType = T;
}

fn main() {
    let _: <(Vec<u32>,) as FieldType<"0">>::FieldType = vec![100];
}

And it prints this error message

error[E0277]: the trait bound `(std::vec::Vec<u32>,): FieldType<"0">` is not satisfied
  --> src/main.rs:12:12
   |
12 |     let _: <(Vec<u32>,) as FieldType<"0">>::FieldType = vec![100];
   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `FieldType<"0">` is not implemented for `(std::vec::Vec<u32>,)`
   |
   = help: the following implementations were found:
             <(T,) as FieldType<"0">>

[Centril]

Reduced:

#![feature(const_generics)]

trait FieldType<const NAME: &'static str> {}

impl FieldType<"0"> for i32 {}

fn main() {
    let _: <i32 as FieldType<"0">>::FieldType;
}

[varkor]

@Centril: that gives a different error, because FieldType isn't defined. Perhaps you meant something like:

#![feature(const_generics)]

trait Trait<const NAME: &'static str> {
    type Assoc;
}

impl Trait<"0"> for () {
    type Assoc = ();
}

fn main() {
    let _: <() as Trait<"0">>::Assoc = ();
}

[varkor]

This appears to be working now.