Macro debug_assert_err_eq

macro_rules! debug_assert_err_eq {
    ($($arg:tt)*) => { ... };
}

Asserts that the left expression contains an Err(E) variant and its contained value of type E equals the right expression in debug builds.

This macro behaves nearly the same as assert_err_eq! on debug builds, although it does not return the value contained in the Err variant. On release builds it is a no-op.