POC stable rust (2 tests failing)

.github/workflows/test.yml

@@ -25,7 +25,7 @@ jobs:
       - name: Install Rust
         uses: actions-rs/toolchain@v1
         with:
-          toolchain: nightly
+          toolchain: stable
           default: true
       - run: rustup set default-host ${{ matrix.platform.rust-target }}
       - name: Build without default features

.travis.yml

@@ -31,7 +31,7 @@ jobs:
 
 env:
   global:
-    - TRAVIS_RUST_VERSION=nightly
+    - TRAVIS_RUST_VERSION=stable
     - RUST_BACKTRACE=1
 
 before_install:

CHANGELOG.md

@@ -6,6 +6,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## [Unreleased]
 ### Added
+- stable rust support
 - Add FFI definition `PyObject_AsFileDescriptor` [#938](https://github.com/PyO3/pyo3/pull/938)
 - Add `PyByteArray::data`, `PyByteArray::as_bytes`, and `PyByteArray::as_bytes_mut`. [#967](https://github.com/PyO3/pyo3/pull/967)
 - Add `Py::borrow`, `Py::borrow_mut`, `Py::try_borrow`, and `Py::try_borrow_mut` for accessing `#[pyclass]` values. [#976](https://github.com/PyO3/pyo3/pull/976)

Cargo.toml

@@ -34,12 +34,10 @@ unindent = { version = "0.1.4", optional = true }
 assert_approx_eq = "1.1.0"
 trybuild = "1.0.23"
 
-[build-dependencies]
-version_check = "0.9.1"
-
 [features]
 default = ["macros"]
 macros = ["ctor", "indoc", "inventory", "paste", "pyo3cls", "unindent"]
+nightly = []
 
 # this is no longer needed internally, but setuptools-rust assumes this feature
 python3 = []

README.md

@@ -16,11 +16,7 @@ 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 1.42.0-nightly 2020-01-21.
-
-If you have never used nightly Rust, the official guide has
-[a great section](https://doc.rust-lang.org/book/appendix-07-nightly-rust.html#rustup-and-the-role-of-rust-nightly)
-about installing it.
+PyO3 supports Python 3.5 and up. The minimum required Rust version is 1.44.
 
 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

@@ -8,13 +8,6 @@ use std::{
     process::{Command, Stdio},
     str::FromStr,
 };
-use version_check::{Channel, Date, Version};
-
-/// Specifies the minimum nightly version needed to compile pyo3.
-/// Keep this synced up with the travis ci config,
-/// But note that this is the rustc version which can be lower than the nightly version
-const MIN_DATE: &str = "2020-01-20";
-const MIN_VERSION: &str = "1.42.0-nightly";
 
 const PY3_MIN_MINOR: u8 = 5;
 const CFG_KEY: &str = "py_sys_config";
@@ -567,34 +560,7 @@ fn check_target_architecture(interpreter_config: &InterpreterConfig) -> Result<(
     Ok(())
 }
 
-fn check_rustc_version() -> Result<()> {
-    let channel = Channel::read().ok_or("Failed to determine rustc channel")?;
-    if !channel.supports_features() {
-        bail!("PyO3 requires a nightly or dev version of Rust.");
-    }
-
-    let actual_version = Version::read().ok_or("Failed to determine the rustc version")?;
-    if !actual_version.at_least(MIN_VERSION) {
-        bail!(
-            "PyO3 requires at least rustc {}, while the current version is {}",
-            MIN_VERSION,
-            actual_version
-        )
-    }
-
-    let actual_date = Date::read().ok_or("Failed to determine the rustc date")?;
-    if !actual_date.at_least(MIN_DATE) {
-        bail!(
-            "PyO3 requires at least rustc {}, while the current rustc date is {}",
-            MIN_DATE,
-            actual_date
-        )
-    }
-    Ok(())
-}
-
 fn main() -> Result<()> {
-    check_rustc_version()?;
     // 1. Setup cfg variables so we can do conditional compilation in this library based on the
     // python interpeter's compilation flags. This is necessary for e.g. matching the right unicode
     // and threading interfaces.  First check if we're cross compiling, if so, we cannot run the

guide/src/rust_cpython.md

@@ -6,7 +6,7 @@ This chapter is based on the discussion in [PyO3/pyo3#55](https://github.com/PyO
 
 ## Macros
 
-While rust-cpython has a macro based dsl for declaring modules and classes, PyO3 uses proc macros and specialization. PyO3 also doesn't change your struct and functions so you can still use them as normal Rust functions. The disadvantage is that specialization currently only works on nightly.
+While rust-cpython has a macro based dsl for declaring modules and classes, PyO3 uses proc macros and specialization. PyO3 also doesn't change your struct and functions so you can still use them as normal Rust functions.
 
 **rust-cpython**
 

src/conversion.rs

@@ -98,6 +98,7 @@ pub trait ToBorrowedObject: ToPyObject {
         F: FnOnce(*mut ffi::PyObject) -> R;
 }
 
+#[cfg(feature = "nightly")]
 impl<T> ToBorrowedObject for T
 where
     T: ToPyObject,
@@ -115,6 +116,25 @@ where
     }
 }
 
+#[cfg(not(feature = "nightly"))]
+impl<T> ToBorrowedObject for T
+where
+    T: ToPyObject,
+{
+    fn with_borrowed_ptr<F, R>(&self, py: Python, f: F) -> R
+    where
+        F: FnOnce(*mut ffi::PyObject) -> R,
+    {
+        let ptr = self.to_object(py).into_ptr();
+        let result = f(ptr);
+        unsafe {
+            ffi::Py_XDECREF(ptr);
+        }
+        result
+    }
+}
+
+#[cfg(feature = "nightly")]
 impl<T> ToBorrowedObject for T
 where
     T: ToPyObject + AsPyPointer,

src/lib.rs

@@ -1,4 +1,4 @@
-#![feature(specialization)]
+#![cfg_attr(nightly, feature(specialization))]
 #![allow(clippy::missing_safety_doc)] // FIXME (#698)
 
 //! Rust bindings to the Python interpreter.

src/types/sequence.rs

@@ -1,5 +1,6 @@
 // Copyright (c) 2017-present PyO3 Project and Contributors
 
+#[cfg(feature = "nightly")]
 use crate::buffer;
 use crate::err::{self, PyDowncastError, PyErr, PyResult};
 use crate::exceptions;
@@ -261,6 +262,7 @@ impl PySequence {
 macro_rules! array_impls {
     ($($N:expr),+) => {
         $(
+            #[cfg(feature = "nightly")]
             impl<'a, T> FromPyObject<'a> for [T; $N]
             where
                 T: Copy + Default + FromPyObject<'a>,
@@ -272,6 +274,19 @@ macro_rules! array_impls {
                 }
             }
 
+            #[cfg(not(feature = "nightly"))]
+            impl<'a, T> FromPyObject<'a> for [T; $N]
+            where
+                T: Copy + Default + FromPyObject<'a>,
+            {
+                fn extract(obj: &'a PyAny) -> PyResult<Self> {
+                    let mut array = [T::default(); $N];
+                    extract_sequence_into_slice(obj, &mut array)?;
+                    Ok(array)
+                }
+            }
+
+            #[cfg(feature = "nightly")]
             impl<'source, T> FromPyObject<'source> for [T; $N]
             where
                 for<'a> T: Copy + Default + FromPyObject<'a> + buffer::Element,
@@ -300,6 +315,17 @@ array_impls!(
     26, 27, 28, 29, 30, 31, 32
 );
 
+#[cfg(not(feature = "nightly"))]
+impl<'a, T> FromPyObject<'a> for Vec<T>
+where
+    T: FromPyObject<'a>,
+{
+    fn extract(obj: &'a PyAny) -> PyResult<Self> {
+        extract_sequence(obj)
+    }
+}
+
+#[cfg(feature = "nightly")]
 impl<'a, T> FromPyObject<'a> for Vec<T>
 where
     T: FromPyObject<'a>,
@@ -309,6 +335,7 @@ where
     }
 }
 
+#[cfg(feature = "nightly")]
 impl<'source, T> FromPyObject<'source> for Vec<T>
 where
     for<'a> T: FromPyObject<'a> + buffer::Element + Copy,

tests/test_datetime.rs

@@ -1,5 +1,6 @@
-#![feature(concat_idents)]
+#![cfg_attr(nightly, feature(concat_idents))]
 
+#[cfg(feature = "nightly")]
 use pyo3::ffi::*;
 use pyo3::prelude::*;
 use pyo3::types::IntoPyDict;
@@ -34,6 +35,7 @@ fn _get_subclasses<'p>(
     Ok((obj, sub_obj, sub_sub_obj))
 }
 
+#[cfg(feature = "nightly")]
 macro_rules! assert_check_exact {
     ($check_func:ident, $obj: expr) => {
         unsafe {
@@ -44,6 +46,7 @@ macro_rules! assert_check_exact {
     };
 }
 
+#[cfg(feature = "nightly")]
 macro_rules! assert_check_only {
     ($check_func:ident, $obj: expr) => {
         unsafe {
@@ -54,6 +57,7 @@ macro_rules! assert_check_only {
     };
 }
 
+#[cfg(feature = "nightly")]
 #[test]
 fn test_date_check() {
     let gil = Python::acquire_gil();
@@ -65,6 +69,7 @@ fn test_date_check() {
     assert_check_only!(PyDate_Check, sub_sub_obj);
 }
 
+#[cfg(feature = "nightly")]
 #[test]
 fn test_time_check() {
     let gil = Python::acquire_gil();
@@ -76,6 +81,7 @@ fn test_time_check() {
     assert_check_only!(PyTime_Check, sub_sub_obj);
 }
 
+#[cfg(feature = "nightly")]
 #[test]
 fn test_datetime_check() {
     let gil = Python::acquire_gil();
@@ -90,6 +96,7 @@ fn test_datetime_check() {
     assert_check_only!(PyDateTime_Check, sub_sub_obj);
 }
 
+#[cfg(feature = "nightly")]
 #[test]
 fn test_delta_check() {
     let gil = Python::acquire_gil();