// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License in the LICENSE-APACHE file or at:
//     https://www.apache.org/licenses/LICENSE-2.0

//! Utilities

use std::fmt;

/// Format for types supporting Debug
///
/// This requires the "spec" feature and nightly rustc to be useful.
pub struct TryFormat<'a, T: ?Sized>(pub &'a T);

#[cfg(not(feature = "spec"))]
impl<'a, T: ?Sized> fmt::Debug for TryFormat<'a, T> {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{{{}}}", std::any::type_name::<T>())
    }
}

#[cfg(feature = "spec")]
impl<'a, T: ?Sized> fmt::Debug for TryFormat<'a, T> {
    default fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{{{}}}", std::any::type_name::<T>())
    }
}

#[cfg(feature = "spec")]
impl<'a, T: fmt::Debug + ?Sized> fmt::Debug for TryFormat<'a, T> {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{:?}", self.0)
    }
}