Enforce Inform Ignore Assume - Gradual Adoption of Contracts in Production Code

Explore a comprehensive conference talk on gradually adopting contract checking in production code. Learn about the four fundamental semantics of contract checks and how to implement them in live systems. Discover the proposed C++23 language support for contracts and practical alternatives using existing libraries. Gain insights into preconditions, postconditions, invariants, and error reporting techniques. Understand the differences between wide and narrow contracts, and how to effectively use contracts in test drivers and unit tests. Examine key issues such as expensive checks and customization options. Follow a step-by-step workflow for implementing contracts, from ignored comments to assumed optimizations, to improve code quality and catch errors early in the development process.

Introduction
Agenda
What is a contract
Examples of contracts
Undefined behavior
Contract no language
Contract no Java
Preconditions
Postconditions
Invariants
Error Reporting
Guarantees
Changing Promises
Finding a Contract
Contract Terminology
Wide vs Narrow Contracts
Survey Results
Example
Post Conditions
Operating Throws
Simple Function
Bug in Implementation
Changing the Contract
Is Another Wide Contract Better
Plug
Contract Tech
Test Drivers vs Unit Tests
C vs C Standard
Key Issues
Expensive Checks
Customization
Contract
The Workflow
Simple First Step