Struct cw_storage_plus::Map

source ·
pub struct Map<'a, K, T> { /* private fields */ }

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.

If you import the proper Map from the remote contract, this will let you read the data from a remote contract in a type-safe way using WasmQuery::RawQuery

Clears the map, removing all elements.

Returns true if the map is empty.

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.

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

Returns a copy of the value. Read more
Performs copy-assignment from source. Read more
Formats the value using the given formatter. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

Should always be Self
The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
Uses borrowed data to replace owned data, usually by cloning. Read more
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.