| FIDL vectors and strings may carry a *size constraint*, which specifies a limit |
| to how many members the type can contain. In the case of vectors this refers to |
| the number of elements stored in the vector, while for strings it refers to the |
| [number of bytes] the string contains. |
| |
| [number of bytes]: /docs/development/api/fidl.md#string_encoding_string_contents_and_length_bounds) |
| |
| The use of size constraints is strongly encouraged, since it sets an upper bound |
| on what would otherwise be an unboundedly large type. |
| |
| <<../examples/key_value_store/_callout.md>> |
| <<../examples/key_value_store/_add_iterator_tutorial.md>> |
