Merge #18030: doc: Coin::IsSpent() can also mean never existed

1404c574037da331c233317618b9b90d3329ed33 [doc] Coin: explain that IsSpent() can also mean never existed (Sjors Provoost)

Pull request description:

  This can be especially confusing where `AccessCoin()` is used with logic like this:

  ```c++
      while (iter.n < MAX_OUTPUTS_PER_BLOCK) {
          const Coin& alternate = view.AccessCoin(iter);
          if (!alternate.IsSpent()) return alternate;
  ```

ACKs for top commit:
  practicalswift:
    ACK 1404c574037da331c233317618b9b90d3329ed33
  MarcoFalke:
    ACK 1404c574037da331c233317618b9b90d3329ed33
  jnewbery:
    utACK 1404c574037da331c233317618b9b90d3329ed33

Tree-SHA512: 418618dd7e08bd5cc8360e3501d0f57e34100e5101ad3b8e0a819923fa860f44c7f2fada0f8447a1af3c2601fd72bfe619b91ff2f26f7133ceaeb0c98b017b12
This commit is contained in:
MarcoFalke 2021-03-23 11:10:58 +01:00 committed by pasta
parent 9ff78a0644
commit cfd9a89298

View File

@ -72,6 +72,9 @@ public:
::Unserialize(s, Using<TxOutCompression>(out));
}
/** Either this coin never existed (see e.g. coinEmpty in coins.cpp), or it
* did exist and has been spent.
*/
bool IsSpent() const {
return out.IsNull();
}