Feat/context #64

Job	Run time
android (-O0)	2m 12s
android (-Ofast -flto -DNDEBUG)	2m 41s
clang-linux (-O0)	2m 33s
clang-linux (-Ofast -flto -DNDEBUG)	2m 34s
clang-linux (-Ofast -flto -DNDEBUG -stdlib=libc++, -stdlib=libc++)	2m 33s
clang-macosx (-O0)	1m 32s
clang-linux (-O0 -stdlib=libc++, -stdlib=libc++)	2m 32s
gcc-linux (-O0)	1m 53s
clang-macosx (-O0 -stdlib=libc++, -stdlib=libc++)	1m 43s
clang-macosx (-Ofast -flto -DNDEBUG)	2m 7s
gcc-linux (-Ofast -flto=auto -DNDEBUG)	1m 56s
clang-macosx (-Ofast -flto -DNDEBUG -stdlib=libc++, -stdlib=libc++)	1m 4s
gcc-macosx (-O0)	45s
gcc-macosx (-Ofast -flto -DNDEBUG)	18s
	26m 23s

Provide feedback