Struct cw_storage_plus::Map [−][src]
pub struct Map<'a, K, T> { /* fields omitted */ }
Implementations
load will return an error if no data is set at the given key, or on parse error
may_load will parse the data stored at the key if present, returns Ok(None) if no data there. returns an error on issues parsing
has returns true or false if any data is at this key, without parsing or interpreting the contents.
Loads the data, perform the specified action, and store the result in the database. This is shorthand for some common sequences, which may be useful.
If the data exists, action(Some(value))
is called. Otherwise action(None)
is called.
While range_raw
over a prefix
fixes the prefix to one element and iterates over the
remaining, prefix_range_raw
accepts bounds for the lowest and highest elements of the Prefix
itself, and iterates over those (inclusively or exclusively, depending on PrefixBound
).
There are some issues that distinguish these two, and blindly casting to Vec<u8>
doesn’t
solve them.
impl<'a, K, T> Map<'a, K, T> where
T: Serialize + DeserializeOwned,
K: PrimaryKey<'a> + KeyDeserialize,
impl<'a, K, T> Map<'a, K, T> where
T: Serialize + DeserializeOwned,
K: PrimaryKey<'a> + KeyDeserialize,
While range
over a prefix
fixes the prefix to one element and iterates over the
remaining, prefix_range
accepts bounds for the lowest and highest elements of the
Prefix
itself, and iterates over those (inclusively or exclusively, depending on
PrefixBound
).
There are some issues that distinguish these two, and blindly casting to Vec<u8>
doesn’t
solve them.
Trait Implementations
Auto Trait Implementations
impl<'a, K, T> RefUnwindSafe for Map<'a, K, T> where
K: RefUnwindSafe,
T: RefUnwindSafe,
impl<'a, K, T> UnwindSafe for Map<'a, K, T> where
K: UnwindSafe,
T: UnwindSafe,
Blanket Implementations
Mutably borrows from an owned value. Read more