Support Rust 1.39.0

.travis.yml

@@ -23,6 +23,9 @@ jobs:
     - name: Nightly
       python: "3.7"
       env: TRAVIS_RUST_VERSION=nightly FEATURES="nightly"
+    - name: Minimum Stable
+      python: "3.7"
+      env: TRAVIS_RUST_VERSION=1.39.0
     - name: PyPy3.5 7.0 # Tested via anaconda PyPy (since travis's PyPy version is too old)
       python: "3.7"
       env: FEATURES="pypy" PATH="$PATH:/opt/anaconda/envs/pypy3/bin"

Cargo.toml

@@ -33,6 +33,7 @@ unindent = { version = "0.1.4", optional = true }
 [dev-dependencies]
 assert_approx_eq = "1.1.0"
 trybuild = "1.0.23"
+rustversion = "1.0"
 
 [features]
 default = ["macros"]

README.md

@@ -4,6 +4,7 @@
 [![Actions Status](https://github.com/PyO3/pyo3/workflows/Test/badge.svg)](https://github.com/PyO3/pyo3/actions)
 [![codecov](https://codecov.io/gh/PyO3/pyo3/branch/master/graph/badge.svg)](https://codecov.io/gh/PyO3/pyo3)
 [![crates.io](http://meritbadge.herokuapp.com/pyo3)](https://crates.io/crates/pyo3)
+[![minimum rustc 1.42](https://img.shields.io/badge/rustc-1.39+-blue.svg)](https://rust-lang.github.io/rfcs/2495-min-rust-version.html)
 [![Join the dev chat](https://img.shields.io/gitter/room/nwjs/nw.js.svg)](https://gitter.im/PyO3/Lobby)
 
 [Rust](http://www.rust-lang.org/) bindings for [Python](https://www.python.org/). This includes running and interacting with Python code from a Rust binary, as well as writing native Python modules.
@@ -16,7 +17,7 @@ A comparison with rust-cpython can be found [in the guide](https://pyo3.rs/maste
 
 ## Usage
 
-PyO3 supports Python 3.5 and up. The minimum required Rust version is 1.44.
+PyO3 supports Python 3.5 and up. The minimum required Rust version is 1.39.0.
 
 PyPy is also supported (via cpyext) for Python 3.5 only, targeted PyPy version is 7.0.0.
 Please refer to the [pypy section in the guide](https://pyo3.rs/master/pypy.html).

build.rs

@@ -69,8 +69,8 @@ impl FromStr for PythonInterpreterKind {
     type Err = Box<dyn std::error::Error>;
     fn from_str(s: &str) -> Result<Self> {
         match s {
-            "CPython" => Ok(Self::CPython),
-            "PyPy" => Ok(Self::PyPy),
+            "CPython" => Ok(PythonInterpreterKind::CPython),
+            "PyPy" => Ok(PythonInterpreterKind::PyPy),
             _ => Err(format!("Invalid interpreter: {}", s).into()),
         }
     }
@@ -295,7 +295,7 @@ fn run_python_script(interpreter: &Path, script: &str) -> Result<String> {
                 );
             }
         }
-        Ok(ok) if !ok.status.success() => bail!("Python script failed: {}"),
+        Ok(ref ok) if !ok.status.success() => bail!("Python script failed: {}"),
         Ok(ok) => Ok(String::from_utf8(ok.stdout)?),
     }
 }

pyo3-derive-backend/src/pyfunction.rs

@@ -179,22 +179,25 @@ pub fn parse_name_attribute(attrs: &mut Vec<syn::Attribute>) -> syn::Result<Opti
         _ => true,
     });
 
-    match &*name_attrs {
-        [] => Ok(None),
-        [(syn::Lit::Str(s), span)] => {
+    if 1 < name_attrs.len() {
+        return Err(syn::Error::new(
+            name_attrs[0].1,
+            "#[name] can not be specified multiple times",
+        ));
+    }
+
+    match name_attrs.get(0) {
+        Some((syn::Lit::Str(s), span)) => {
             let mut ident: syn::Ident = s.parse()?;
             // This span is the whole attribute span, which is nicer for reporting errors.
             ident.set_span(*span);
             Ok(Some(ident))
         }
-        [(_, span)] => Err(syn::Error::new(
+        Some((_, span)) => Err(syn::Error::new(
             *span,
             "Expected string literal for #[name] argument",
         )),
-        [(_, span), ..] => Err(syn::Error::new(
-            *span,
-            "#[name] can not be specified multiple times",
-        )),
+        None => Ok(None),
     }
 }
 

pyo3-derive-backend/src/pymethod.rs

@@ -512,10 +512,11 @@ fn impl_arg_param(
         };
         if let syn::Type::Reference(tref) = ty {
             let (tref, mut_) = tref_preprocess(tref);
-            let as_deref = if mut_.is_some() {
-                quote! { as_deref_mut }
+            // To support Rustc 1.39.0, we don't use as_deref here...
+            let tmp_as_deref = if mut_.is_some() {
+                quote! { _tmp.as_mut().map(std::ops::DerefMut::deref_mut) }
             } else {
-                quote! { as_deref }
+                quote! { _tmp.as_ref().map(std::ops::Deref::deref) }
             };
             // Get Option<&T> from Option<PyRef<T>>
             quote! {
@@ -525,7 +526,7 @@ fn impl_arg_param(
                     },
                     None => #default,
                 };
-                let #arg_name = _tmp.#as_deref();
+                let #arg_name = #tmp_as_deref;
             }
         } else {
             quote! {
@@ -731,8 +732,9 @@ pub(crate) fn impl_py_getter_def(
 
 /// Split an argument of pyo3::Python from the front of the arg list, if present
 fn split_off_python_arg<'a>(args: &'a [FnArg<'a>]) -> (Option<&FnArg>, &[FnArg]) {
-    match args {
-        [py, rest @ ..] if utils::if_type_is_python(&py.ty) => (Some(py), rest),
-        rest => (None, rest),
+    if args.get(0).map(|py| utils::if_type_is_python(&py.ty)) == Some(true) {
+        (Some(&args[0]), &args[1..])
+    } else {
+        (None, args)
     }
 }

tests/test_compile_error.rs

@@ -1,13 +1,23 @@
 #[test]
 fn test_compile_errors() {
     let t = trybuild::TestCases::new();
-    t.compile_fail("tests/ui/invalid_macro_args.rs");
-    t.compile_fail("tests/ui/invalid_property_args.rs");
-    t.compile_fail("tests/ui/invalid_pyclass_args.rs");
-    t.compile_fail("tests/ui/missing_clone.rs");
-    t.compile_fail("tests/ui/reject_generics.rs");
-    t.compile_fail("tests/ui/wrong_aspyref_lifetimes.rs");
-    t.compile_fail("tests/ui/static_ref.rs");
-    #[cfg(not(feature = "nightly"))]
-    t.compile_fail("tests/ui/invalid_pymethod_names.rs");
+    testcase_common(&t);
+    testcase_latest_stable(&t);
+
+    fn testcase_common(t: &trybuild::TestCases) {
+        t.compile_fail("tests/ui/invalid_macro_args.rs");
+        t.compile_fail("tests/ui/invalid_property_args.rs");
+        t.compile_fail("tests/ui/invalid_pyclass_args.rs");
+        t.compile_fail("tests/ui/missing_clone.rs");
+        t.compile_fail("tests/ui/reject_generics.rs");
+        t.compile_fail("tests/ui/wrong_aspyref_lifetimes.rs");
+        t.compile_fail("tests/ui/invalid_pymethod_names.rs");
+    }
+
+    #[rustversion::all(since(1.43))]
+    fn testcase_latest_stable(t: &trybuild::TestCases) {
+        t.compile_fail("tests/ui/static_ref.rs");
+    }
+    #[rustversion::before(1.43)]
+    fn testcase_latest_stable(_t: &trybuild::TestCases) {}
 }