If you exchange property and the gain was exactly zero, is this a taxable event?

Question for the legal experts: If you exchange property in a single transaction and there is exactly zero capital gain, is this a taxable event?

Examples:

1. If I buy a gift card with a $100 value from Amazon, and then I later use this gift card to make a purchase, would I be required to report the transaction where I consumed the value of the gift card even though I did not incur a gain? (I know no one would report it, I just want legal clarification).

2. If I buy a gold coin from someone on Craigslist for exactly $1300.00 and later sell it for exactly $1300.00, what should I do (I did not incur a capital gain)?

3. If I bought a gold coin from Person A for exactly $1300.00 and a gold coin from Person B for $1000.00, melted both coins down and forged a new gold coin, and then sold this coin for exactly $2300.00, what should I do (I did not incur a capital gain)?