Updated and added new functions related to headers, resolved ODR issues, resolved clang-tidy warnings #351

	name: ubuntu-latest-clang-ci

	on:
	workflow_dispatch:

	push:
	branches:
	- master
	- feature/**
	- improvement/**
	- bugfix/**

	pull_request:
	branches:
	- master
	- feature/**
	- improvement/**
	- bugfix/**

	jobs:
	clang_tests:
	if: >-
	! contains(toJSON(github.event.commits.*.message), '[skip ci]') &&
	! contains(toJSON(github.event.commits.*.message), '[skip github]')

	strategy:
	matrix:
	# cmake clang12 is not able to compile a simple test program.
	# /usr/bin/ld: cannot find -lunwind
	version: ['latest', '15', '14', '13', '11', '10', '9', '8', '7']
	type: [Release, Debug]

	runs-on: ubuntu-latest

	name: "Clang ${{matrix.version}}: ${{matrix.type}}"

	container:
	image: silkeh/clang:${{matrix.version}}
	options: -v /usr/local:/host_usr_local

	env:
	CC: clang
	CXX: clang++
	CXXFLAGS: -stdlib=libc++

	steps:
	- uses: actions/checkout@v1

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

	- name: CMake
	run: echo "/host_usr_local/bin" >> $GITHUB_PATH

	- name: Install dependencies
	run: \|
	apt-get update
	apt-get install -y git
	script/ci_install_deps.sh

	- name: Configure
	run: cmake -S test -B build -DCMAKE_BUILD_TYPE=${{matrix.type}}

	- name: Build
	run: cmake --build build -j ${{steps.cores.outputs.count}}

	- name: Run
	working-directory: build
	run: ctest --output-on-failure

Provide feedback