040000 tree aab493cdc464fcac4e5bce443041a82ea8e428aa	internal
100644 blob bc6a421a07987fc1f3765852e447e1118e135229	optional.h
100644 blob 20ea7a6392d597df0d3dd644bca53ee20ba1c1fe	type_traits.h
100644 blob d981ea6bd4432f8d087dbf21db1be0c4452cab6a	utility.h
100644 blob c022e4b30a54b9c759385e848216e1598c3606b2	version.h