2_idioms

Step 2: Idioms

Estimated time: 2 days

These steps describe common idioms required for writing well-designed and idiomatic Rust code.

❗️Before completing this step you should complete all its sub-steps.

After doing them you should be able to answer the following questions:

• Why should I care about types and expressing things in types? How do types help to increase guarantees of a program being correct?
• What is essential for writing well-designed and ergonomic APIs in Rust and why?
• Why mem::replace exists and what purpose does it solve? When and why is it really helpful?
• How input type polymorphism is usually organized in Rust APIs? What cost does it have?
• Which ways and tools do exist for future-proofing source code in Rust?

Task

Design and implement a VendingMachine type, which behaves like a vending machine:

• Product should have a price and a name;
• VendingMachine should have a limited capacity of Products;
• VendingMachine should be able to give change;
• VendingMachine should reject purchase if it cannot give change;
• Coin nominal values could only be 1, 2, 5, 10, 20 and 50.

Make its usage API as convenient as you're capable to.