Preconditions, Postconditions, Invariants: How They Help Write Robust Programs - Andrzej Krzemieński

In this talk you will see:
1. How thinking in these terms helps us write code more consciously and with fewer bugs.
2. How these terms are reflected today in code (spoiler: comments, assert() and "contract-encoding" types).
3. How different tools, like static analyzers or IDEs, can be improved if things like preconditions can be expressed directly in code.
4. What the difference is between a bug and a symptom of a bug, and how to fix bugs rather than conceal their symptoms.

No prior knowledge of the subject is assumed. By the end of the talk:
1. You will appreciate and be willing to apply the Design by Contract methodology, even if it means putting more asserts() and comments in your code.
2. You should be able to tell why a "contract" is not a sum of preconditions, postconditions and invariants.
3. You will understand how "contract-encoding" types and preconditions/invariants are complementary features.