non_std 0.1.4

Collection of general purpose tools for solving problems. Fundamentally extend the language without spoiling, so may be used solely or in conjunction with another module of such kind.
Documentation
#![ cfg_attr( not( feature = "use_std" ), no_std ) ]
#![ doc( html_logo_url = "https://raw.githubusercontent.com/Wandalen/wTools/master/asset/img/logo_v3_trans_square.png" ) ]
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#![ doc( html_root_url = "https://docs.rs/is_slice/latest/is_slice/" ) ]
#![ warn( rust_2018_idioms ) ]
#![ warn( missing_debug_implementations ) ]
#![ warn( missing_docs ) ]

//!
//! Macro to answer the question: is it a slice?
//!

#![ doc = include_str!( concat!( env!( "CARGO_MANIFEST_DIR" ), "/Readme.md" ) ) ]

/// Internal namespace.
pub( crate ) mod private
{

  /// Macro to answer the question: is it a slice?
  ///
  /// ### Sample
  /// ```
  /// use is_slice::*;
  ///
  /// fn main()
  /// {
  ///   dbg!( is_slice!( Box::new( true ) ) );
  ///   // < is_slice!(Box :: new(true)) = false
  ///   dbg!( is_slice!( &[ 1, 2, 3 ] ) );
  ///   // < is_slice!(& [1, 2, 3]) = false
  ///   dbg!( is_slice!( &[ 1, 2, 3 ][ .. ] ) );
  ///   // < is_slice!(& [1, 2, 3] [..]) = true
  /// }
  /// ```

  #[ macro_export ]
  macro_rules! is_slice
  {
    ( $V : expr ) =>
    {{
      use ::core::marker::PhantomData;

      trait NotSlice
      {
        fn is_slice( self : &'_ Self ) -> bool { false }
      }

      impl< T > NotSlice
      for &'_ PhantomData< T >
      where T : ?Sized,
      {}

      trait Slice
      {
        fn is_slice( self : &'_ Self ) -> bool { true }
      }

      impl< 'a, T > Slice for PhantomData< &'a &[ T ] >
      {}

      fn does< T : Sized >( _ : &T ) -> PhantomData< &T >
      {
        PhantomData
      }

      ( &does( &$V ) ).is_slice()

    }}
  }

  pub use is_slice;
}

/// Protected namespace of the module.
pub mod protected
{
  pub use super::orphan::*;
}

#[ doc( inline ) ]
pub use protected::*;

/// Orphan namespace of the module.
pub mod orphan
{
  pub use super::exposed::*;
}

/// Exposed namespace of the module.
pub mod exposed
{
  pub use super::prelude::*;
}

/// Prelude to use essentials: `use my_module::prelude::*`.
pub mod prelude
{
  #[ doc( inline ) ]
  pub use super::private::
  {
    is_slice,
  };
}