src/test/ui/issues/issue-48551.rs

// build-pass (FIXME(62277): could be check-pass?)
// Regression test for #48551. Covers a case where duplicate candidates
// arose during associated type projection.

use std::ops::{Mul, MulAssign};

pub trait ClosedMul<Right>: Sized + Mul<Right, Output = Self> + MulAssign<Right> {}
impl<T, Right> ClosedMul<Right> for T
where
    T: Mul<Right, Output = T> + MulAssign<Right>,
{
}

pub trait InnerSpace: ClosedMul<<Self as InnerSpace>::Real> {
    type Real;
}

pub trait FiniteDimVectorSpace: ClosedMul<<Self as FiniteDimVectorSpace>::Field> {
    type Field;
}

pub trait FiniteDimInnerSpace
    : InnerSpace + FiniteDimVectorSpace<Field = <Self as InnerSpace>::Real> {
}

pub trait EuclideanSpace: ClosedMul<<Self as EuclideanSpace>::Real> {
    type Coordinates: FiniteDimInnerSpace<Real = Self::Real>
        + Mul<Self::Real, Output = Self::Coordinates>
        + MulAssign<Self::Real>;

    type Real;
}

fn main() {}