improve continuous integration #72

	on:
	push:
	branches:
	- master
	- ci
	pull_request:
	branches:
	- master
	- ci

	name: Rust

	jobs:
	runner-matrix:
	name: format, lint, test
	strategy:
	matrix:
	os: [ubuntu-latest, windows-latest, macos-latest]
	runs-on: ${{ matrix.os }}
	steps:
	- name: Checkout sources
	uses: actions/checkout@v3

	- name: Install stable toolchain
	uses: actions-rs/toolchain@v1
	with:
	profile: minimal
	toolchain: stable
	override: true
	components: rustfmt, clippy

	# build with latest stable, but reset CI cache when new versions of Rust are released
	- name: Determine build cache key
	id: vars
	run: \|
	RUST_VERSION=$(rustc -V \| grep -Po '(?<=^rustc )\S+')
	echo "rustc-version=$RUST_VERSION" >> $GITHUB_OUTPUT

	# Don't include target/ -- only cache building 3rd-party libraries.
	- name: Use build cache
	uses: actions/cache@v3
	with:
	path: \|
	~/.cargo/bin/
	~/.cargo/registry/index/
	~/.cargo/registry/cache/
	~/.cargo/git/db/
	target/
	key: ${{ runner.os }}-cargo-${{ steps.vars.outputs.rustc-version }}-${{ hashFiles('**/Cargo.lock') }}

	- name: Run cargo fmt
	uses: actions-rs/cargo@v1
	with:
	command: fmt
	args: --all -- --check

	- name: Run cargo clippy
	uses: actions-rs/cargo@v1
	with:
	command: clippy
	args: -- -D warnings

	- name: Run cargo test
	uses: actions-rs/cargo@v1
	with:
	command: test

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