Require generic associated types

.github/workflows/test.yml

@@ -40,10 +40,11 @@ jobs:
       fail-fast: false
       matrix:
         os: [macos-latest, windows-latest]
-        toolchain: [stable]
+        # TODO: use stable once GATs reach stable
+        toolchain: [beta]
         include:
           - os: ubuntu-latest
-            toolchain: "1.58.0"
+            toolchain: "1.65.0"
           - os: ubuntu-latest
             toolchain: beta
 

Cargo.toml

@@ -30,9 +30,6 @@ harfbuzz = ["harfbuzz_rs"]
 # Enable Markdown parsing
 markdown = ["pulldown-cmark"]
 
-# Use Generic Associated Types (experimental)
-gat = []
-
 # Serialization is optionally supported for some types:
 # serde
 

README.md

@@ -62,6 +62,12 @@ Non-pure-Rust alternatives include [font-kit](https://crates.io/crates/font-kit)
 and [piet](https://crates.io/crates/piet) among others.
 
 
+MSRV
+---
+
+The Minium Supported Rust Version is 1.65.0.
+
+
 Contributing
 --------
 

src/fonts/library.rs

@@ -130,6 +130,9 @@ impl<'a> FaceStore<'a> {
 
 #[derive(Default)]
 struct FaceList {
+    // Safety: unsafe code depends on entries never moving (hence the otherwise
+    // redundant use of Box). See e.g. FontLibrary::get_face().
+    #[allow(clippy::vec_box)]
     faces: Vec<Box<FaceStore<'static>>>,
     // These are vec-maps. Why? Because length should be short.
     path_hash: Vec<(u64, FaceId)>,

src/fonts/selector.rs

@@ -38,7 +38,7 @@ enum State {
 fn to_uppercase<'a>(c: Cow<'a, str>) -> Cow<'a, str> {
     match c {
         Cow::Borrowed(b) if !b.chars().any(|c| c.is_lowercase()) => Cow::Borrowed(b),
-        c => Cow::Owned(c.to_owned().to_uppercase()),
+        c => Cow::Owned(c.to_uppercase()),
     }
 }
 

src/format.rs

@@ -21,15 +21,7 @@ pub use markdown::{Error as MarkdownError, Markdown};
 ///
 /// Any `F: FormattableText` automatically support [`FormattableTextDyn`].
 /// Implement either this or [`FormattableTextDyn`], not both.
-///
-/// This trait can only be written as intended using Generic Associated Types
-/// (`gat`, unstable nightly feature), thus `font_tokens` has a different
-/// signature with/without feature `gat` and the associated type
-/// `FontTokenIter` is only present with feature `gat`.
 pub trait FormattableText: std::fmt::Debug {
-    #[cfg_attr(doc_cfg, doc(cfg(feature = "gat")))]
-    #[cfg(feature = "gat")]
-    // TODO: rename → Iter
     type FontTokenIter<'a>: Iterator<Item = FontToken>
     where
         Self: 'a;
@@ -53,20 +45,8 @@ pub trait FormattableText: std::fmt::Debug {
     /// The `dpem` parameter is font size as in [`crate::Environment`].
     ///
     /// For plain text this iterator will be empty.
-    #[cfg(feature = "gat")]
     fn font_tokens<'a>(&'a self, dpem: f32) -> Self::FontTokenIter<'a>;
 
-    /// Construct an iterator over formatting items
-    ///
-    /// It is expected that [`FontToken::start`] of yielded items is strictly
-    /// increasing; if not, formatting may not be applied correctly.
-    ///
-    /// The `dpem` parameter is font size as in [`crate::Environment`].
-    ///
-    /// For plain text this iterator will be empty.
-    #[cfg(not(feature = "gat"))]
-    fn font_tokens(&self, dpem: f32) -> OwningVecIter<FontToken>;
-
     /// Get the sequence of effect tokens
     ///
     /// This method has some limitations: (1) it may only return a reference to
@@ -117,7 +97,6 @@ pub trait FormattableTextDyn: std::fmt::Debug {
     fn effect_tokens(&self) -> &[Effect<()>];
 }
 
-// #[cfg(feature = "gat")]
 impl<F: FormattableText + Clone + 'static> FormattableTextDyn for F {
     fn clone_boxed(&self) -> Box<dyn FormattableTextDyn> {
         Box::new(self.clone())
@@ -132,14 +111,7 @@ impl<F: FormattableText + Clone + 'static> FormattableTextDyn for F {
 
     fn font_tokens(&self, dpem: f32) -> OwningVecIter<FontToken> {
         let iter = FormattableText::font_tokens(self, dpem);
-        #[cfg(feature = "gat")]
-        {
-            OwningVecIter::new(iter.collect())
-        }
-        #[cfg(not(feature = "gat"))]
-        {
-            iter
-        }
+        OwningVecIter::new(iter.collect())
     }
 
     fn effect_tokens(&self) -> &[Effect<()>] {
@@ -148,11 +120,9 @@ impl<F: FormattableText + Clone + 'static> FormattableTextDyn for F {
 }
 
 impl<'t> FormattableText for &'t dyn FormattableTextDyn {
-    #[cfg(feature = "gat")]
-    type FontTokenIter<'a>
+    type FontTokenIter<'a> = OwningVecIter<FontToken>
     where
-        Self: 'a,
-    = OwningVecIter<FontToken>;
+        Self: 'a,;
 
     #[inline]
     fn str_len(&self) -> usize {

src/format/markdown.rs

@@ -8,8 +8,6 @@
 use super::{EditableText, FontToken, FormattableText};
 use crate::conv::to_u32;
 use crate::fonts::{self, FontId, FontSelector, Style, Weight};
-#[cfg(not(feature = "gat"))]
-use crate::OwningVecIter;
 use crate::{Effect, EffectFlags};
 use pulldown_cmark::{Event, HeadingLevel, Tag};
 use std::fmt::Write;
@@ -108,25 +106,17 @@ impl<'a> ExactSizeIterator for FontTokenIter<'a> {}
 impl<'a> FusedIterator for FontTokenIter<'a> {}
 
 impl FormattableText for Markdown {
-    #[cfg(feature = "gat")]
     type FontTokenIter<'a> = FontTokenIter<'a>;
 
     #[inline]
     fn as_str(&self) -> &str {
         &self.text
     }
 
-    #[cfg(feature = "gat")]
     #[inline]
     fn font_tokens<'a>(&'a self, dpem: f32) -> Self::FontTokenIter<'a> {
         FontTokenIter::new(&self.fmt, dpem)
     }
-    #[cfg(not(feature = "gat"))]
-    #[inline]
-    fn font_tokens(&self, dpem: f32) -> OwningVecIter<FontToken> {
-        let iter = FontTokenIter::new(&self.fmt, dpem);
-        OwningVecIter::new(iter.collect())
-    }
 
     fn effect_tokens(&self) -> &[Effect<()>] {
         &self.effects

src/format/plain.rs

@@ -7,50 +7,35 @@
 
 use super::{EditableText, FontToken, FormattableText};
 use crate::Effect;
-#[cfg(not(feature = "gat"))]
-use crate::OwningVecIter;
 
 impl<'t> FormattableText for &'t str {
-    #[cfg(feature = "gat")]
-    type FontTokenIter<'a>
+    type FontTokenIter<'a> = std::iter::Empty<FontToken>
     where
-        Self: 'a,
-    = std::iter::Empty<FontToken>;
+        Self: 'a;
 
     fn as_str(&self) -> &str {
         self
     }
 
-    #[cfg(feature = "gat")]
     fn font_tokens<'a>(&'a self, _: f32) -> Self::FontTokenIter<'a> {
         std::iter::empty()
     }
-    #[cfg(not(feature = "gat"))]
-    fn font_tokens(&self, _: f32) -> OwningVecIter<FontToken> {
-        OwningVecIter::new(Vec::new())
-    }
 
     fn effect_tokens(&self) -> &[Effect<()>] {
         &[]
     }
 }
 
 impl FormattableText for String {
-    #[cfg(feature = "gat")]
     type FontTokenIter<'a> = std::iter::Empty<FontToken>;
 
     fn as_str(&self) -> &str {
         self
     }
 
-    #[cfg(feature = "gat")]
     fn font_tokens<'a>(&'a self, _: f32) -> Self::FontTokenIter<'a> {
         std::iter::empty()
     }
-    #[cfg(not(feature = "gat"))]
-    fn font_tokens(&self, _: f32) -> OwningVecIter<FontToken> {
-        OwningVecIter::new(Vec::new())
-    }
 
     fn effect_tokens(&self) -> &[Effect<()>] {
         &[]

src/lib.rs

@@ -14,7 +14,6 @@
 //! [`format`]: mod@format
 
 #![cfg_attr(doc_cfg, feature(doc_cfg))]
-#![cfg_attr(feature = "gat", feature(generic_associated_types))]
 #![allow(clippy::len_zero)]
 #![allow(clippy::type_complexity)]
 #![allow(clippy::unit_arg)]