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 sole? When and why is it really helpful?

Task

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

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

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