devela/code/util/
_reexport.rs

// devela::code::util::_reexport
//
//! private reexport meta helper
//

/// Macro helper for documentation of re-exported items.
//
// FIX: unresolved link to `alloc`.
// IMPROVE: make dependencies safety related to features.
// IMPROVE: rendered paths with trailing `::`. E.g.:
// - Re-exported from std::backtrace:: .
// - Re-exported from [alloc]::boxed:: .
// - Re-exported from core::array:: IntoIter→ArrayIntoIter.
// MAYBE: new branch for: either a crate or core (for portable-atomic types).
macro_rules! reexport {
    /* re-exports from normal modules */

    // the following 4 arms allows reexporting items from:
    // `core`, `alloc`, `std` or `no_std`|`std`.
    //
    // - Supports multiple re-exported items.
    // - Renamed items must be all at the end, and each one prefixed with @.
    //
    // # Examples
    // ```
    // reexport! { rust: core::any, local_module: "any",
    //     "Represents a globally unique identifier for a type.", TypeId }
    // ```
    ( // when the item is available in `core`
      rust : core $( :: $( $core_path:ident )::+)?,
      $( local_module: $module_feature:literal, )?
      $( extra_features: $($extraf:literal),+ $(,)? )?
      $( tag: $tag:expr, )?
      doc: $description:literal,
      $( $item:ident ),*
      $(@ $item_to_rename:ident as $item_renamed:ident),*
      $(,)?
    ) => { $crate::paste! {
        #[doc(inline)]
        $( #[doc = $tag] )?
        #[doc = "<span class='stab portability' title='re-exported from rust&#39;s "
        "`core`'>`core`</span>"]
        #[doc = $description]
        #[doc = "\n\n*Re-exported from [`core" $( "`]::[`" $( $core_path "::" )+ )?
            "`](https://doc.rust-lang.org/core/" $($( $core_path "/" )+)? ")*"]

        #[doc = $("`" $item_to_rename "`→[`" $item_renamed "`]")* ".\n\n---"]

        #[cfg_attr(feature = "nightly_doc", doc(cfg(all(
            $( feature = $module_feature, )?
            $( all($(feature = $extraf),+) )?
        ))))]
        #[cfg(all(
            $( $(feature = $extraf),+ )?
        ))]
        pub use core :: $($( $core_path :: )+)? {
            $( $item ),*
            $( $item_to_rename as $item_renamed ),*
        };
    }};
    // when the item is available in `alloc`
    ( rust : alloc $( :: $( $alloc_path:ident )::+)?,
      $( local_module: $module_feature:literal, )?
      $( tag: $tag:expr, )?
      doc: $description:literal,
      $( $item:ident ),*
      $(@ $item_to_rename:ident as $item_renamed:ident),*
      $(,)?
    ) => { $crate::paste! {
        #[doc(inline)]
        #[allow(rustdoc::broken_intra_doc_links)] // TEMP FIX unresolved link to alloc
        $( #[doc = $tag] )?
        #[doc = "<span class='stab portability' title='re-exported from rust&#39;s "
        "`alloc`'>`alloc`</span>"]
        #[doc = $description]
        #[doc = "\n\n*Re-exported from [`alloc" $( "`]::[`" $( $alloc_path "::" )+ )?
            "`](https://doc.rust-lang.org/alloc/" $($( $alloc_path "/" )+)? ")*"]

        #[doc = $("`" $item_to_rename "`→[`" $item_renamed "`]")* ".\n\n---"]

        #[cfg_attr(
            feature = "nightly_doc",
            doc(cfg(all(
                $( feature = $module_feature, )?
                feature = "alloc"
            )))
        )]

        #[cfg(feature = "alloc")]
        pub use crate::_dep::_alloc :: $($( $alloc_path :: )+)? {
            $( $item ),*
            $( $item_to_rename as $item_renamed ),*
        };
    }};
    ( // when the item is available in `std`
      rust : std $( :: $( $std_path:ident )::+)?,
      $( local_module: $module_feature:literal, )?
      $( tag: $tag:expr, )?
      doc: $description:literal,
      $( $item:ident ),*
      $(@ $item_to_rename:ident as $item_renamed:ident),*
      $(,)?
    ) => { $crate::paste! {
        #[doc(inline)]
        $( #[doc = $tag] )?
        #[doc = "<span class='stab portability' title='re-exported from rust&#39;s "
        "`std`'>`std`</span>"]
        #[doc = $description]
        #[doc = "\n\n*Re-exported from [`std" $( "`]::[`" $( $std_path "::" )+ )?
            "`](https://doc.rust-lang.org/std/" $($( $std_path "/" )+)? ")*"]

        #[doc = $("`" $item_to_rename "`→[`" $item_renamed "`]")* ".\n\n---"]

        #[cfg_attr(
            feature = "nightly_doc",
            doc(cfg(all(
                $( feature = $module_feature, )?
                feature = "std"
            )))
        )]

        #[cfg(feature = "std")]
        pub use std :: $($( $std_path :: )+)? {
            $( $item ),*
            $( $item_to_rename as $item_renamed ),*
        };
    }};
    ( // when the item is available in either `no_std` or `std`
      rust : no_std|std $( :: $( $std_path:ident )::+)?,
      $( local_module: $module_feature:literal, )?
      $( tag: $tag:expr, )?
      doc: $description:literal,
      $( $item:ident ),*
      $(@ $item_to_rename:ident as $item_renamed:ident),*
      $(,)?
    ) => { $crate::paste! {
        #[doc(inline)]
        $( #[doc = $tag] )?
        /// <span class='stab portability' title='re-exported from rust&#39;s `std`
        /// or recreated for `no_std`'>`[no_]std`</span>
        #[doc = $description]
        #[doc = "\n\n*Re-exported from [`std" $( "`]::[`" $( $std_path "::" )+ )?
            "`](https://doc.rust-lang.org/std/" $($( $std_path "/" )+)? ")*"]

        #[doc = $("`" $item_to_rename "`→[`" $item_renamed "`]")* ".\n\n---"]

        #[cfg_attr(
            feature = "nightly_doc",
            doc(cfg(all(
                $( feature = $module_feature, )?
                any(feature = "std", feature = "no_std")
            )))
        )]

        #[cfg(feature = "std")]
        pub use std :: $($( $std_path :: )+)? {
            $( $item ),*
            $( $item_to_rename as $item_renamed ),*
        };
    }};

    ( // when the item is available in either `not(std)` or `std` (always, more transparent)
      rust : not(std)|std $( :: $( $std_path:ident )::+)?,
      $( local_module: $module_feature:literal, )?
      $( tag: $tag:expr, )?
      doc: $description:literal,
      $( $item:ident ),*
      $(@ $item_to_rename:ident as $item_renamed:ident),*
      $(,)?
    ) => { $crate::paste! {
        #[doc(inline)]
        $( #[doc = $tag] )?
        /// <span class='stab portability' title='re-exported from rust&#39;s `std`
        /// or recreated if `not(std)`'>`?std`</span>
        #[doc = $description]
        #[doc = "\n\n*Re-exported from [`std" $( "`]::[`" $( $std_path "::" )+ )?
            "`](https://doc.rust-lang.org/std/" $($( $std_path "/" )+)? ")*"]

        #[doc = $("`" $item_to_rename "`→[`" $item_renamed "`]")* ".\n\n---"]

        #[cfg_attr(
            feature = "nightly_doc",
            doc(cfg(all(
                $( feature = $module_feature, )?
            )))
        )]

        #[cfg(feature = "std")]
        pub use std :: $($( $std_path :: )+)? {
            $( $item ),*
            $( $item_to_rename as $item_renamed ),*
        };
    }};
    (
      /* external dependencies */

      // Re-exports a non-optional crate
      crate $dep_str:literal | $dep:ident,
      doc: $description:literal
      $(, features: $( $f:literal ),+ )?
    ) => { $crate::paste! {
        #[doc = "<span class='stab portability' title='re-exported `" $dep_str
            "`'>`" $dep_str "`</span>"]
        #[doc = $description "\n\n---" ]
        #[doc(inline)]
        pub use ::$dep;
    }};
    (
      // Re-exports an optional crate
      //
      // $dep_safe:    [safe|unsafe] (affects compilation with "safest" feature)
      // $dep_feat:    the dependency feature name
      // $dep_name:    the dependency real name
      // $dep_mod:     the dependency module name
      // $description: the dependency decription
      // $f:           additional features needed
      optional_crate ($dep_safe:tt)
      $dep_feat:literal, $dep_name:literal, $dep_mod:ident,
      doc: $description:literal
      $(, features: $( $f:literal ),+ )?
    ) => { $crate::paste! {
        #[cfg(all(feature = $dep_feat $(, $(feature = $f),+ )? ))]
        $crate::items! {
            // safety-guard: panics if `safest` is enabled and dependency is not safe
            #[cfg(feature = "safest")]
            #[$crate::compile(diff($dep_safe, safe))]
            const [<SAFEST_ $dep_name:upper>]: () = { panic![concat!["The `", $dep_name,
            "` dependency is not compatible with the `safest` feature"]] };

            #[doc = "<span class='stab portability' title='re-exported `" $dep_name
                "`'>`" $dep_name "`</span>"]
            #[doc = $description "\n\n---" ]
            #[cfg_attr(
                feature = "nightly_doc",
                doc(cfg(all(
                    feature = $dep_feat $(, $(feature = $f)+ )?
                )))
            )]
            #[doc(inline)]
            pub use ::$dep_mod;
        }
    }};
    (
      // re-exports items from an external optional dependency, from any normal module.
      //
      // - Supports multiple re-exported items.
      // - Renamed items must be all at the end, and each one prefixed with @.
      //
      // $dep_feat:    the dependency feature
      // $dep_name:    the dependency name
      // $dep_mod:     the dependency module
      // $f:           additional features needed
      // $description: the dependency decription
      // $item:
      // $item_to_rename:
      // $item_renamed:
      $dep_feat:literal, $dep_name:literal, $dep_mod:ident $( :: $dep_path:path)?,
      $( features: $( $f:literal ),+ ,)?
      $( tag: $tag:expr, )?
      doc: $description:literal,
      $( $item:ident ),*
      $(@ $item_to_rename:ident as $item_renamed:ident),*
      $(,)?
    ) => { $crate::paste! {
        #[doc(inline)]
        $( #[doc = $tag] )?
        #[doc = "<span class='stab portability' title='re-exported from the `"
            $dep_name "` crate'>`" $dep_name "`</span>"]
        #[doc = $description]
        #[doc = "\n\n*Re-exported from the [`" $dep_name
            "`](https://docs.rs/" $dep_name " ) crate*"]

        #[doc = $("`" $item_to_rename "`→[`" $item_renamed "`]")* ".\n\n---"]

        // IMPROVE: can't use like this for portable-atomic | core::atomic,
        // should remove depend from here for the portable-atomic part,
        // but leave it in the following cfg attribute.
        // Also, the part of negated features and target_has_atomic
        // would require a different branch
        #[cfg_attr(
            feature = "nightly_doc",
            doc(cfg(all(
                feature = $dep_feat $(, $(feature = $f)+ )?
            )))
        )]

        #[cfg(all(feature = $dep_feat $(, $(feature = $f),+ )? ))]
        pub use crate::_dep::$dep_mod $( ::$dep_path )? :: {
            $( $item ),*
            $( $item_to_rename as $item_renamed ),*
        };
    }};
    (
      // re-exports items from an external non-optional dependency, from any normal module.
      //
      // - Supports multiple re-exported items.
      // - Renamed items must be all at the end, and each one prefixed with @.
      //
      // in the past it was used for: result::Either
      non-optional $dep_str:literal | $dep:ident $( :: $dep_path:path)?,
      $( features: $( $f:literal ),+ ,)?
      $( local_module: $module_feature:literal ,)?
      $( tag: $tag:expr, )?
      doc: $description:literal,
      $( $item:ident ),*
      $(@ $item_to_rename:ident as $item_renamed:ident),*
      $(,)?
    ) => { $crate::paste! {
        #[doc(inline)]
        $( #[doc = $tag] )?
        #[doc = "<span class='stab portability' title='re-exported from the `" $dep_str
            "` crate'>`" $dep_str "`</span>"]
        #[doc = $description]
        #[doc = "\n\n*Re-exported from the [`" $dep_str
            "`](https://docs.rs/" $dep_str " ) crate*"]

        #[doc = $("`" $item_to_rename "`→[`" $item_renamed "`]")* ".\n\n---"]

        #[cfg_attr(feature = "nightly_doc", doc(cfg(all(
            $( feature = $module_feature ,)?
            $( $( feature = $f ),+ )?
        ))))]
        #[cfg(all( $($( feature = $f )+)? ))]

        pub use ::$dep $( ::$dep_path )? :: {
            $( $item ),*
            $( $item_to_rename as $item_renamed ),*
        };
    }};
}
pub(crate) use reexport;
devela/code/util/_reexport.rs

devela/code/util/
_reexport.rs
