Bump MSRV to 1.56

.cargo/config

@@ -3,10 +3,6 @@ xtask = "run --package xtask --"
 
 [target.'cfg(feature = "cargo-clippy")']
 rustflags = [
-    # TODO: remove these allows once msrv increased from 1.48
-    "-Aclippy::iter_kv_map",
-    "-Aclippy::needless_borrow",
-    "-Aclippy::uninlined_format_args",
     # Lints to enforce in CI
     "-Dclippy::checked_conversions",
     "-Dclippy::dbg_macro",
@@ -15,7 +11,6 @@ rustflags = [
     "-Dclippy::filter_map_next",
     "-Dclippy::flat_map_option",
     "-Dclippy::let_unit_value",
-    "-Dclippy::manual_assert",
     "-Dclippy::manual_ok_or",
     "-Dclippy::todo",
     "-Dclippy::unnecessary_wraps",

.github/workflows/build.yml

@@ -201,7 +201,3 @@ jobs:
       # TODO: this is a hack to workaround compile_error! warnings about auto-initialize on PyPy
       # Once cargo's `resolver = "2"` is stable (~ MSRV Rust 1.52), remove this.
       PYO3_CI: 1
-      # This is a hack to make CARGO_PRIMARY_PACKAGE always set even for the
-      # msrv job. MSRV is currently 1.48, but CARGO_PRIMARY_PACKAGE only came in
-      # 1.49.
-      CARGO_PRIMARY_PACKAGE: 1

.github/workflows/ci.yml

@@ -81,7 +81,7 @@ jobs:
           },
         ]
         include:
-          - rust: 1.48.0
+          - rust: 1.56.0
             python-version: "3.11"
             platform:
               {
@@ -207,7 +207,7 @@ jobs:
           ]
         include:
           # Test minimal supported Rust version
-          - rust: 1.48.0
+          - rust: 1.56.0
             python-version: "3.11"
             platform:
               {

Cargo.toml

@@ -12,6 +12,7 @@ categories = ["api-bindings", "development-tools::ffi"]
 license = "Apache-2.0"
 exclude = ["/.gitignore", ".cargo/config", "/codecov.yml", "/Makefile", "/pyproject.toml", "/noxfile.py", "/.github", "/tests/test_compile_error.rs", "/tests/ui"]
 edition = "2018"
+rust-version = "1.56"
 
 [dependencies]
 cfg-if = "1.0"

README.md

@@ -4,7 +4,7 @@
 [![benchmark](https://github.com/PyO3/pyo3/actions/workflows/bench.yml/badge.svg)](https://pyo3.rs/dev/bench/)
 [![codecov](https://codecov.io/gh/PyO3/pyo3/branch/main/graph/badge.svg)](https://codecov.io/gh/PyO3/pyo3)
 [![crates.io](https://img.shields.io/crates/v/pyo3)](https://crates.io/crates/pyo3)
-[![minimum rustc 1.48](https://img.shields.io/badge/rustc-1.48+-blue.svg)](https://rust-lang.github.io/rfcs/2495-min-rust-version.html)
+[![minimum rustc 1.56](https://img.shields.io/badge/rustc-1.56+-blue.svg)](https://rust-lang.github.io/rfcs/2495-min-rust-version.html)
 [![dev chat](https://img.shields.io/gitter/room/nwjs/nw.js.svg)](https://gitter.im/PyO3/Lobby)
 [![contributing notes](https://img.shields.io/badge/contribute-on%20github-Green)](https://github.com/PyO3/pyo3/blob/main/Contributing.md)
 
@@ -18,7 +18,7 @@
 
 PyO3 supports the following software versions:
   - Python 3.7 and up (CPython and PyPy)
-  - Rust 1.48 and up
+  - Rust 1.56 and up
 
 You can use PyO3 to write a native Python module in Rust, or to embed Python in a Rust binary. The following sections explain each of these in turn.
 

examples/plugin/plugin_api/pyproject.toml

@@ -10,5 +10,3 @@ classifiers = [
     "Programming Language :: Python :: Implementation :: CPython",
     "Programming Language :: Python :: Implementation :: PyPy",
 ]
-
-

guide/src/getting_started.md

@@ -4,7 +4,7 @@ To get started using PyO3 you will need three things: a Rust toolchain, a Python
 
 ## Rust
 
-First, make sure you have Rust installed on your system. If you haven't already done so, try following the instructions [here](https://www.rust-lang.org/tools/install). PyO3 runs on both the `stable` and `nightly` versions so you can choose whichever one fits you best. The minimum required Rust version is 1.48.
+First, make sure you have Rust installed on your system. If you haven't already done so, try following the instructions [here](https://www.rust-lang.org/tools/install). PyO3 runs on both the `stable` and `nightly` versions so you can choose whichever one fits you best. The minimum required Rust version is 1.56.
 
 If you can run `rustc --version` and the version is new enough you're good to go!
 

guide/src/migration.md

@@ -3,6 +3,12 @@
 This guide can help you upgrade code through breaking changes from one PyO3 version to the next.
 For a detailed list of all changes, see the [CHANGELOG](changelog.md).
 
+## from 0.19.* to 0.20
+
+### Drop support for older technologies
+
+PyO3 0.20 has increased minimum Rust version to 1.56. This enables use of newer language features and simplifies maintenance of the project.
+
 ## from 0.18.* to 0.19
 
 ### Access to `Python` inside `__traverse__` implementations are now forbidden

newsfragments/3208.packaging.md

@@ -0,0 +1 @@
+Update MSRV to Rust 1.56.

pyo3-ffi/README.md

@@ -14,7 +14,7 @@ Manual][capi] for up-to-date documentation.
 
 PyO3 supports the following software versions:
   - Python 3.7 and up (CPython and PyPy)
-  - Rust 1.48 and up
+  - Rust 1.56 and up
 
 # Example: Building Python Native modules
 

pyo3-ffi/src/lib.rs

@@ -51,7 +51,7 @@
 //!
 //! PyO3 supports the following software versions:
 //!   - Python 3.7 and up (CPython and PyPy)
-//!   - Rust 1.48 and up
+//!   - Rust 1.56 and up
 //!
 //! # Example: Building Python Native modules
 //!

pyo3-macros-backend/src/pyfunction/signature.rs

@@ -27,10 +27,11 @@ pub struct Signature {
 impl Parse for Signature {
     fn parse(input: ParseStream<'_>) -> syn::Result<Self> {
         let content;
-        Ok(Signature {
-            paren_token: syn::parenthesized!(content in input),
-            items: content.parse_terminated(SignatureItem::parse)?,
-        })
+        let paren_token = syn::parenthesized!(content in input);
+
+        let items = content.parse_terminated(SignatureItem::parse)?;
+
+        Ok(Signature { paren_token, items })
     }
 }
 

src/lib.rs

@@ -122,7 +122,7 @@
 //!
 //! PyO3 supports the following software versions:
 //!   - Python 3.7 and up (CPython and PyPy)
-//!   - Rust 1.48 and up
+//!   - Rust 1.56 and up
 //!
 //! # Example: Building a native Python module
 //!

xtask/src/cli.rs

@@ -5,7 +5,7 @@ use std::process::{Command, Output};
 use std::time::Instant;
 use structopt::StructOpt;
 
-pub const MSRV: &str = "1.48";
+pub const MSRV: &str = "1.56";
 
 #[derive(StructOpt)]
 pub enum Subcommand {