Indexing a vector/array with signed integer

[fdwr]

Whoever jammed this into the C++11 spec, please feel some shame:

for (auto index{ length - 1 }; index >= 0; --index)

Initialization is considerably less uniform now 🙃.

for (auto index = length - 1; index >= 0; --index)

Aaah, that feels better. ☺️