Add simplified implementation in `subproject/simple` #257

	name: Continuous Integration

	on:
	push:
	branches:
	- master

	pull_request:
	branches:
	- master

	env:
	CC: /usr/bin/gcc-10
	CXX: /usr/bin/g++-10

	jobs:
	tests:
	runs-on: ubuntu-latest

	steps:
	- uses: actions/checkout@v3

	- uses: friendlyanon/fetch-core-count@v1
	id: cores

	- name: Install GCC 10
	run: \|
	sudo apt-get update
	sudo apt-get install -y gcc-10 g++-10

	- name: Configure
	run: cmake -Ssubproject/test -Bbuild/test
	-DCMAKE_BUILD_TYPE:STRING=Debug

	- name: Build
	run: cmake --build build/test --config Debug
	-j ${{ steps.cores.outputs.plus_one }}

	- name: Test
	run: \|
	cd build/test
	ctest -C Debug --output-on-failure -j ${{ steps.cores.outputs.plus_one }}

	build_meta:
	runs-on: ubuntu-latest

	steps:
	- uses: actions/checkout@v3

	- uses: friendlyanon/fetch-core-count@v1
	id: cores

	- name: Install GCC 10
	run: \|
	sudo apt-get update
	sudo apt-get install -y gcc-10 g++-10

	- name: Configure
	run: cmake -Ssubproject/meta -Bbuild/meta
	-DCMAKE_BUILD_TYPE:STRING=Debug

	- name: Build
	run: cmake --build build/meta --config Debug
	-j ${{ steps.cores.outputs.plus_one }}

	build_benchmark:
	runs-on: ubuntu-latest

	steps:
	- uses: actions/checkout@v3

	- uses: friendlyanon/fetch-core-count@v1
	id: cores

	- name: Install GCC 10
	run: \|
	sudo apt-get update
	sudo apt-get install -y gcc-10 g++-10

	- name: Configure
	run: cmake -Ssubproject/benchmark -Bbuild/benchmark
	-DCMAKE_BUILD_TYPE:STRING=Debug

	- name: Build
	run: cmake --build build/benchmark --config Debug
	-j ${{ steps.cores.outputs.plus_one }}

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