/// Marks errors that may be safely shown to a client.
/// This trait can be seen as a specialized version of [`ToString`].
///
/// NOTE: This trait should not be implemented for [`anyhow::Error`], since it
/// is way too convenient and tends to proliferate all across the codebase,
/// ultimately leading to accidental leaks of sensitive data.
pub trait UserFacingError: ToString {
    /// Format the error for client, stripping all sensitive info.
    ///
    /// Although this might be a no-op for many types, it's highly
    /// recommended to override the default impl in case error type
    /// contains anything sensitive: various IDs, IP addresses etc.
    #[inline(always)]
    fn to_string_client(&self) -> String {
        self.to_string()
    }
}