fix(lib): use precise capturing on 1.82+

.github/workflows/rustlib.yml

@@ -1,8 +1,8 @@
 on:
   pull_request:
     paths:
-    - '**.rs'
-    - '**/Cargo.toml'
+      - "**.rs"
+      - "**/Cargo.toml"
   workflow_dispatch:
 
 name: Library testing
@@ -12,47 +12,51 @@ jobs:
     name: Rustdoc
     runs-on: ubuntu-latest
     steps:
-    - name: Checkout sources
-      uses: actions/checkout@v4
+      - name: Checkout sources
+        uses: actions/checkout@v4
 
-    - name: Install nightly toolchain
-      uses: dtolnay/rust-toolchain@nightly
+      - name: Install nightly toolchain
+        uses: dtolnay/rust-toolchain@nightly
 
-    - name: Cache dependencies
-      uses: Swatinem/rust-cache@v2
+      - name: Cache dependencies
+        uses: Swatinem/rust-cache@v2
 
-    - name: Check rustdoc build
-      run: RUSTDOCFLAGS='--cfg docsrs' cargo +nightly doc --features debug -Zunstable-options -Zrustdoc-scrape-examples
+      - name: Check rustdoc build
+        run: RUSTDOCFLAGS='--cfg docsrs' cargo +nightly doc --features debug -Zunstable-options -Zrustdoc-scrape-examples
 
   tests:
     name: Tests
     strategy:
       matrix:
         rust:
-        - stable
-        - beta
-        - nightly
+          - 1.70.0 # current MSRV
+          - 1.82.0 # precise capturing
+          - stable
+          - beta
+          - nightly
         os:
-        - macos-latest
-        - ubuntu-latest
-        - windows-latest
+          - macos-latest
+          - ubuntu-latest
+          - windows-latest
         features:
-        - ""  # default features
-        - "--features forbid_unsafe"
+          - "" # default features
+          - "--features forbid_unsafe"
 
     runs-on: ${{ matrix.os }}
     steps:
-    - name: Checkout sources
-      uses: actions/checkout@v4
-
-    - name: Install stable toolchain
-      uses: dtolnay/rust-toolchain@stable
-
-    - name: Cache dependencies
-      uses: Swatinem/rust-cache@v2
-
-    - name: Check that tests run
-      uses: actions-rs/cargo@v1
-      with:
-        command: test
-        args: --workspace --verbose ${{ matrix.features }}
+      - name: Checkout sources
+        uses: actions/checkout@v4
+
+      - name: Install stable toolchain
+        uses: dtolnay/rust-toolchain@stable
+        with:
+          toolchain: ${{ matrix.rust }}
+
+      - name: Cache dependencies
+        uses: Swatinem/rust-cache@v2
+
+      - name: Check that tests run
+        uses: actions-rs/cargo@v1
+        with:
+          command: test
+          args: --workspace --verbose ${{ matrix.features }}

logos-codegen/Cargo.toml

@@ -11,6 +11,9 @@ syn = { version = "2.0.13", features = ["full"] }
 pretty_assertions = "1.4.0"
 rstest = "0.18.2"
 
+[build-dependencies]
+rustc_version = "0.4.1"
+
 [features]
 # Enables debug messages
 debug = []

logos-codegen/build.rs

@@ -0,0 +1,17 @@
+use rustc_version::{version_meta, Version};
+
+fn main() {
+    let version_meta = version_meta().expect("Could not get Rust version");
+
+    let rustc_version = version_meta.semver;
+    let trimmed_rustc_version = Version::new(
+        rustc_version.major,
+        rustc_version.minor,
+        rustc_version.patch,
+    );
+
+    println!("cargo:rustc-check-cfg=cfg(rust_1_82)");
+    if trimmed_rustc_version >= Version::new(1, 82, 0) {
+        println!("cargo:rustc-cfg=rust_1_82");
+    }
+}

logos-codegen/src/generator/leaf.rs

@@ -28,11 +28,17 @@ impl<'a> Generator<'a> {
                 let arg = &inline.arg;
                 let body = &inline.body;
 
+                #[cfg(not(rust_1_82))]
+                let ret = quote!(impl CallbackResult<'s, #ty, #this>);
+
+                #[cfg(rust_1_82)]
+                let ret = quote!(impl CallbackResult<'s, #ty, #this> + use<'a>);
+
                 quote! {
                     #bump
 
                     #[inline]
-                    fn callback<'s>(#arg: &mut Lexer<'s>) -> impl CallbackResult<'s, #ty, #this> {
+                    fn callback<'s>(#arg: &mut Lexer<'s>) -> #ret {
                         #body
                     }