Updates to singleton_base #371

	name: gcc-c++11
	on:
	push:
	branches: [ master, development, pull-request/* ]
	pull_request:
	branches: [ master, pull-request/* ]

	jobs:

	build-gcc-cpp11-linux-stl:
	name: GCC C++11 Linux - STL
	runs-on: ${{ matrix.os }}
	strategy:
	matrix:
	os: [ubuntu-22.04]

	steps:
	- uses: actions/checkout@v4

	- name: Build
	run: \|
	git fetch
	export ASAN_OPTIONS=alloc_dealloc_mismatch=0,detect_leaks=0
	export CC=gcc
	export CXX=g++
	cmake -DBUILD_TESTS=ON -DNO_STL=OFF -DETL_USE_TYPE_TRAITS_BUILTINS=OFF -DETL_USER_DEFINED_TYPE_TRAITS=OFF -DETL_FORCE_TEST_CPP03=OFF -DETL_CXX_STANDARD=11 ./
	gcc --version
	make -j $(getconf _NPROCESSORS_ONLN)

	- name: Run tests
	run: ./test/etl_tests

	build-gcc-cpp11-linux-no-stl:
	name: GCC C++11 Linux - No STL
	runs-on: ${{ matrix.os }}
	strategy:
	matrix:
	os: [ubuntu-22.04]

	steps:
	- uses: actions/checkout@v4

	- name: Build
	run: \|
	git fetch
	export ASAN_OPTIONS=alloc_dealloc_mismatch=0,detect_leaks=0
	export CC=gcc
	export CXX=g++
	cmake -DBUILD_TESTS=ON -DNO_STL=ON -DETL_USE_TYPE_TRAITS_BUILTINS=OFF -DETL_USER_DEFINED_TYPE_TRAITS=OFF -DETL_FORCE_TEST_CPP03=OFF -DETL_CXX_STANDARD=11 ./
	gcc --version
	make -j $(getconf _NPROCESSORS_ONLN)

	- name: Run tests
	run: ./test/etl_tests

Provide feedback