MapGetOrDefault
Description
Get the first value stored for a key, or return a fallback value copy.
This returns a value copy, not a pointer. The fallback value is not inserted into the map. If you want insertion-on-miss semantics, use
MapEnsurePtr.
Parameters
| Name | Direction | Description |
|---|---|---|
m |
in,out | Map. |
lookup_key |
in | Key to search for. |
default_value |
in | Value returned when key does not exist. |
Success
Returns a value of type MAP_VALUE_TYPE(m) - either a copy of the first stored value for the key, or a copy of default_value when the key is absent. The map is not modified; default_value is not inserted.
Failure
Does not return on invalid arguments (caller bug); aborts via LOG_FATAL.
Usage example (Cross-references)
Usage examples (Cross-references)
- In
Access.c:235:
// MapGetOrDefault on an empty map returns the default, inserts nothing.
int got = MapGetOrDefault(&map, 7, 1234);
result = result && (got == 1234);
result = result && (MapPairCount(&map) == 0);- In
Access.c:253:
MapInsertR(&map, 11, 111);
int found = MapGetOrDefault(&map, 11, 999);
int miss = MapGetOrDefault(&map, 999, 555);
bool result = (found == 110);- In
Access.c:254:
int found = MapGetOrDefault(&map, 11, 999);
int miss = MapGetOrDefault(&map, 999, 555);
bool result = (found == 110);
result = result && (miss == 555);
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