Validate unsigned operations?

[nuzzle]

Do you know of any clever strategy to trace such cases at debug runtime, without having to add asserts all over the code? It's important that it does not affect performance in release mode.

You could systematically seek higher level language constructs. For example instead of integer counters in for-loops you can use iterators, or the new for-each loop in C++ 11, or BOOST_FOREACH/BOOST_REVERSE_FOREACH. The Boost way is my favourite. You can easily, safely and quickly loop over every standard data structure.

Start programming at a higher abstraction level and avoid low level fiddling. It's not as efficient as one might think and it's error-prone. Seek the highest abstraction level that's reasonable and optimize only when necessary at proven bottlenecks.