pqu: add DEBUG tests, empty() #783

	name: Minor C/C++ CI

	on:
	push:
	branches-ignore:
	- 'ignore*'
	- 'temp*'
	- smoke
	- master
	paths-ignore:
	- 'docs/*'
	pull_request:
	paths-ignore:
	- 'docs/*'
	branches-ignore:
	- smoke
	- master

	jobs:
	linux:
	runs-on: ubuntu-latest
	timeout-minutes: 30
	strategy:
	fail-fast: false
	matrix:
	MAKE:
	- make -j4 SANITIZE=1 O0=1
	- make -j4 CC='gcc -std=c99'
	- make -j4 CC='gcc -std=c11'
	- make -j4 CXX='clang++-11 -std=c++2a -stdlib=libc++'
	- make examples SANITIZE=1
	- make perf
	steps:
	# needed for libc++ since the Ubuntu 20.04.2 update (image version 20210315.1)
	# https://askubuntu.com/questions/1211743/clang-doesnt-find-c-stdlib-on-my-ubuntu-18-04-but-it-does-on-a-brand-new-ins
	# variant 1: downgrade clang++ to matching g++ (= 11)
	- if: ${{ contains(matrix.MAKE, 'libc++') }}
	run: \|
	sudo apt-get install clang++-11 libc++-11-dev libc++abi-11-dev
	clang++ --version
	sudo update-alternatives --install /usr/bin/clang++ clang++ /usr/bin/clang++-11 100
	clang++ --version
	g++ --version
	- uses: actions/checkout@v2
	- run: ${{ matrix.MAKE }}
	windows:
	runs-on: windows-latest
	steps:
	- uses: actions/checkout@v2
	- uses: ilammy/msvc-dev-cmd@v1
	- run: nmake -f Makefile.win all
	macOS:
	runs-on: macos-latest
	steps:
	- uses: actions/checkout@v2
	- run: make CXX='c++ -std=c++17'

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