feat(zero-sized): add zero-sized Display types, change `Printable{I…

…ter, Tuple}` signatures

CHANGELOG.md

@@ -6,10 +6,19 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 <!-- next-header -->
 
+## [2.0.0] - 2024-05-15
+### Added
+- `auxiliary::SpacedComma`
+- `auxiliary::LeftSquareBracket`
+- `auxiliary::RightSquareBracket`
+### Changed
+- `PrintableIter` and `PrintableTuple` signatures
+
 ## [1.0.0] - 2024-05-15
 ### Added
 - `PrintableIter`
 - `PrintableTuple`
 
 <!-- next-url -->
+[2.0.0]: https://github.com/andrewsonin/lazy_ref/releases/tag/v2.0.0
 [1.0.0]: https://github.com/andrewsonin/lazy_ref/releases/tag/v1.0.0

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "printable"
-version = "1.0.1"
+version = "2.0.0"
 authors = ["Andrew Sonin <sonin.cel@yandex.ru>"]
 categories = ["value-formatting"]
 description = "Provides `std::fmt::Display` wrapper for iterators and tuples."

src/auxiliary.rs

@@ -0,0 +1,37 @@
+use std::fmt::{Debug, Display, Formatter, Write};
+
+/// Zero-sized type, which is displayed as `, `.
+#[derive(Debug)]
+#[repr(transparent)]
+pub struct SpacedComma;
+
+impl Display for SpacedComma {
+    #[inline]
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        f.write_str(", ")
+    }
+}
+
+/// Zero-sized type, which is displayed as `[`.
+#[derive(Debug)]
+#[repr(transparent)]
+pub struct LeftSquareBracket;
+
+impl Display for LeftSquareBracket {
+    #[inline]
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        f.write_char('[')
+    }
+}
+
+/// Zero-sized type, which is displayed as `]`.
+#[derive(Debug)]
+#[repr(transparent)]
+pub struct RightSquareBracket;
+
+impl Display for RightSquareBracket {
+    #[inline]
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        f.write_char(']')
+    }
+}

src/iter.rs

@@ -1,3 +1,4 @@
+use crate::auxiliary::{LeftSquareBracket, RightSquareBracket, SpacedComma};
 use std::fmt::{Display, Formatter};
 
 use crate::wrapper::{DisplayWithSep, PrintableWrapper};
@@ -54,14 +55,15 @@ where
     #[inline]
     fn printable(
         self,
-    ) -> PrintableWrapper<&'static str, &'static str, &'static str, IterHandler<Self>> {
+    ) -> PrintableWrapper<SpacedComma, LeftSquareBracket, RightSquareBracket, IterHandler<Self>>
+    {
         #[cfg(feature = "unstable-assert-no-drop")]
         let () = Self::NO_DROP_CHECK;
         PrintableWrapper {
             inner: IterHandler(self),
-            sep: ", ",
-            left_bound: "[",
-            right_bound: "]",
+            sep: SpacedComma,
+            left_bound: LeftSquareBracket,
+            right_bound: RightSquareBracket,
         }
     }
 }
@@ -74,7 +76,12 @@ where
 }
 
 impl<T> From<T>
-    for PrintableWrapper<&'static str, &'static str, &'static str, IterHandler<T::IntoIter>>
+    for PrintableWrapper<
+        SpacedComma,
+        LeftSquareBracket,
+        RightSquareBracket,
+        IterHandler<T::IntoIter>,
+    >
 where
     T: IntoIterator,
     T::Item: Display,

src/lib.rs

@@ -1,6 +1,8 @@
 #![doc = include_str!("../README.md")]
 #![allow(clippy::module_name_repetitions)]
 
+/// Implements various auxiliary utilities.
+pub mod auxiliary;
 /// Implements [`Display`](std::fmt::Display) wrapper for iterators.
 pub mod iter;
 /// Implements [`Display`](std::fmt::Display) wrapper for tuples.

src/tuple.rs

@@ -1,6 +1,10 @@
 use std::fmt::{Display, Formatter};
 
-use crate::{prelude::PrintableWrapper, wrapper::DisplayWithSep};
+use crate::{
+    auxiliary::{LeftSquareBracket, RightSquareBracket, SpacedComma},
+    prelude::PrintableWrapper,
+    wrapper::DisplayWithSep,
+};
 
 /// Wraps tuples into [`PrintableWrapper`].
 ///
@@ -20,12 +24,13 @@ pub trait PrintableTuple: Sized {
     #[inline]
     fn printable(
         self,
-    ) -> PrintableWrapper<&'static str, &'static str, &'static str, TupleHandler<Self>> {
+    ) -> PrintableWrapper<SpacedComma, LeftSquareBracket, RightSquareBracket, TupleHandler<Self>>
+    {
         PrintableWrapper {
             inner: TupleHandler(self),
-            sep: ", ",
-            left_bound: "[",
-            right_bound: "]",
+            sep: SpacedComma,
+            left_bound: LeftSquareBracket,
+            right_bound: RightSquareBracket,
         }
     }
 }