Struct diesel_pg_hstore::Hstore

pub struct Hstore(_);

The Hstore wrapper type.

Methods

impl Hstore

fn new() -> Hstore

Create a new Hstore object

fn from_hashmap(hm: HashMap<String, String>) -> Hstore

Create a new Hstore from an existing hashmap

use diesel_pg_hstore::Hstore;
use std::collections::HashMap;

let mut settings = HashMap::new();
settings.insert("Hello".into(), "World".into());

let settings_hstore = Hstore::from_hashmap(settings);

fn with_capacity(capacity: usize) -> Hstore

Please see HashMap.with_capacity

fn capacity(&self) -> usize

Please see HashMap.capacity

fn reserve(&mut self, additional: usize)

Please see HashMap.reserve

fn shrink_to_fit(&mut self)

Please see HashMap.shrink_to_fit

fn keys(&self) -> Keys<String, String>

Please see HashMap.keys

fn values(&self) -> Values<String, String>

Please see HashMap.values

fn values_mut(&mut self) -> ValuesMut<String, String>

Please see HashMap.values_mut

fn iter(&self) -> Iter<String, String>

Please see HashMap.iter

fn iter_mut(&mut self) -> IterMut<String, String>

Please see HashMap.iter_mut

fn entry(&mut self, key: String) -> Entry<String, String>

Please see HashMap.entry

fn len(&self) -> usize

Please see HashMap.len

fn is_empty(&self) -> bool

Please see HashMap.is_empty

fn drain(&mut self) -> Drain<String, String>

Please see HashMap.drain

fn clear(&mut self)

Please see HashMap.clear

fn get(&self, k: &str) -> Option<&String>

Please see HashMap.get

fn get_mut(&mut self, k: &str) -> Option<&mut String>

Please see HashMap.get_mut

fn contains_key(&self, k: &str) -> bool

Please see HashMap.contains_key

fn insert(&mut self, k: String, v: String) -> Option<String>

Please see HashMap.insert

fn remove(&mut self, k: &str) -> Option<String>

Please see HashMap.remove

fn retain<F>(&mut self, f: F) where
    F: FnMut(&String, &mut String) -> bool, 

Please see HashMap.retain

Methods from Deref<Target = HashMap<String, String>>

fn hasher(&self) -> &S

Returns a reference to the map's BuildHasher.

fn capacity(&self) -> usize

Returns the number of elements the map can hold without reallocating.

This number is a lower bound; the HashMap<K, V> might be able to hold more, but is guaranteed to be able to hold at least this many.

Examples

use std::collections::HashMap;
let map: HashMap<isize, isize> = HashMap::with_capacity(100);
assert!(map.capacity() >= 100);

fn reserve(&mut self, additional: usize)

Reserves capacity for at least additional more elements to be inserted in the HashMap. The collection may reserve more space to avoid frequent reallocations.

Panics

Panics if the new allocation size overflows usize.

Examples

use std::collections::HashMap;
let mut map: HashMap<&str, isize> = HashMap::new();
map.reserve(10);

fn shrink_to_fit(&mut self)

Shrinks the capacity of the map as much as possible. It will drop down as much as possible while maintaining the internal rules and possibly leaving some space in accordance with the resize policy.

Examples

use std::collections::HashMap;

let mut map: HashMap<isize, isize> = HashMap::with_capacity(100);
map.insert(1, 2);
map.insert(3, 4);
assert!(map.capacity() >= 100);
map.shrink_to_fit();
assert!(map.capacity() >= 2);

fn keys(&self) -> Keys<K, V>

An iterator visiting all keys in arbitrary order. The iterator element type is &'a K.

Examples

use std::collections::HashMap;

let mut map = HashMap::new();
map.insert("a", 1);
map.insert("b", 2);
map.insert("c", 3);

for key in map.keys() {
    println!("{}", key);
}

fn values(&self) -> Values<K, V>

An iterator visiting all values in arbitrary order. The iterator element type is &'a V.

Examples

use std::collections::HashMap;

let mut map = HashMap::new();
map.insert("a", 1);
map.insert("b", 2);
map.insert("c", 3);

for val in map.values() {
    println!("{}", val);
}

fn values_mut(&mut self) -> ValuesMut<K, V>

An iterator visiting all values mutably in arbitrary order. The iterator element type is &'a mut V.

Examples

use std::collections::HashMap;

let mut map = HashMap::new();

map.insert("a", 1);
map.insert("b", 2);
map.insert("c", 3);

for val in map.values_mut() {
    *val = *val + 10;
}

for val in map.values() {
    println!("{}", val);
}

fn iter(&self) -> Iter<K, V>

An iterator visiting all key-value pairs in arbitrary order. The iterator element type is (&'a K, &'a V).

Examples

use std::collections::HashMap;

let mut map = HashMap::new();
map.insert("a", 1);
map.insert("b", 2);
map.insert("c", 3);

for (key, val) in map.iter() {
    println!("key: {} val: {}", key, val);
}

fn iter_mut(&mut self) -> IterMut<K, V>

An iterator visiting all key-value pairs in arbitrary order, with mutable references to the values. The iterator element type is (&'a K, &'a mut V).

Examples

use std::collections::HashMap;

let mut map = HashMap::new();
map.insert("a", 1);
map.insert("b", 2);
map.insert("c", 3);

// Update all values
for (_, val) in map.iter_mut() {
    *val *= 2;
}

for (key, val) in &map {
    println!("key: {} val: {}", key, val);
}

fn entry(&mut self, key: K) -> Entry<K, V>

Gets the given key's corresponding entry in the map for in-place manipulation.

Examples

use std::collections::HashMap;

let mut letters = HashMap::new();

for ch in "a short treatise on fungi".chars() {
    let counter = letters.entry(ch).or_insert(0);
    *counter += 1;
}

assert_eq!(letters[&'s'], 2);
assert_eq!(letters[&'t'], 3);
assert_eq!(letters[&'u'], 1);
assert_eq!(letters.get(&'y'), None);

fn len(&self) -> usize

Returns the number of elements in the map.

Examples

use std::collections::HashMap;

let mut a = HashMap::new();
assert_eq!(a.len(), 0);
a.insert(1, "a");
assert_eq!(a.len(), 1);

fn is_empty(&self) -> bool

Returns true if the map contains no elements.

Examples

use std::collections::HashMap;

let mut a = HashMap::new();
assert!(a.is_empty());
a.insert(1, "a");
assert!(!a.is_empty());

fn drain(&mut self) -> Drain<K, V>

Clears the map, returning all key-value pairs as an iterator. Keeps the allocated memory for reuse.

Examples

use std::collections::HashMap;

let mut a = HashMap::new();
a.insert(1, "a");
a.insert(2, "b");

for (k, v) in a.drain().take(1) {
    assert!(k == 1 || k == 2);
    assert!(v == "a" || v == "b");
}

assert!(a.is_empty());

fn clear(&mut self)

Clears the map, removing all key-value pairs. Keeps the allocated memory for reuse.

Examples

use std::collections::HashMap;

let mut a = HashMap::new();
a.insert(1, "a");
a.clear();
assert!(a.is_empty());

fn get<Q>(&self, k: &Q) -> Option<&V> where
    K: Borrow<Q>,
    Q: Hash + Eq + ?Sized, 

Returns a reference to the value corresponding to the key.

The key may be any borrowed form of the map's key type, but Hash and Eq on the borrowed form must match those for the key type.

Examples

use std::collections::HashMap;

let mut map = HashMap::new();
map.insert(1, "a");
assert_eq!(map.get(&1), Some(&"a"));
assert_eq!(map.get(&2), None);

fn contains_key<Q>(&self, k: &Q) -> bool where
    K: Borrow<Q>,
    Q: Hash + Eq + ?Sized, 

Returns true if the map contains a value for the specified key.

The key may be any borrowed form of the map's key type, but Hash and Eq on the borrowed form must match those for the key type.

Examples

use std::collections::HashMap;

let mut map = HashMap::new();
map.insert(1, "a");
assert_eq!(map.contains_key(&1), true);
assert_eq!(map.contains_key(&2), false);

fn get_mut<Q>(&mut self, k: &Q) -> Option<&mut V> where
    K: Borrow<Q>,
    Q: Hash + Eq + ?Sized, 

Returns a mutable reference to the value corresponding to the key.

The key may be any borrowed form of the map's key type, but Hash and Eq on the borrowed form must match those for the key type.

Examples

use std::collections::HashMap;

let mut map = HashMap::new();
map.insert(1, "a");
if let Some(x) = map.get_mut(&1) {
    *x = "b";
}
assert_eq!(map[&1], "b");

fn insert(&mut self, k: K, v: V) -> Option<V>

Inserts a key-value pair into the map.

If the map did not have this key present, None is returned.

If the map did have this key present, the value is updated, and the old value is returned. The key is not updated, though; this matters for types that can be == without being identical. See the module-level documentation for more.

Examples

use std::collections::HashMap;

let mut map = HashMap::new();
assert_eq!(map.insert(37, "a"), None);
assert_eq!(map.is_empty(), false);

map.insert(37, "b");
assert_eq!(map.insert(37, "c"), Some("b"));
assert_eq!(map[&37], "c");

fn remove<Q>(&mut self, k: &Q) -> Option<V> where
    K: Borrow<Q>,
    Q: Hash + Eq + ?Sized, 

Removes a key from the map, returning the value at the key if the key was previously in the map.

The key may be any borrowed form of the map's key type, but Hash and Eq on the borrowed form must match those for the key type.

Examples

use std::collections::HashMap;

let mut map = HashMap::new();
map.insert(1, "a");
assert_eq!(map.remove(&1), Some("a"));
assert_eq!(map.remove(&1), None);

fn retain<F>(&mut self, f: F) where
    F: FnMut(&K, &mut V) -> bool, 

Retains only the elements specified by the predicate.

In other words, remove all pairs (k, v) such that f(&k,&mut v) returns false.

Examples

use std::collections::HashMap;

let mut map: HashMap<isize, isize> = (0..8).map(|x|(x, x*10)).collect();
map.retain(|&k, _| k % 2 == 0);
assert_eq!(map.len(), 4);

Trait Implementations

impl NotNull for Hstore

impl SingleValue for Hstore

impl Queryable<Hstore, Pg> for Hstore

type Row = Self

fn build(row: Self::Row) -> Self

impl<'a> AsExpression<Hstore> for &'a Hstore

type Expression = Bound<Hstore, &'a Hstore>

fn as_expression(self) -> Self::Expression

impl FromSql<Hstore, Pg> for Hstore

fn from_sql(bytes: Option<&[u8]>) -> Result<Self, Box<StdError + Send + Sync>>

impl FromSqlRow<Hstore, Pg> for Hstore

fn build_from_row<T: Row<Pg>>(
    row: &mut T
) -> Result<Self, Box<StdError + Send + Sync>>

const FIELDS_NEEDED: usize

The number of fields that this type will consume. Must be equal to the number of times you would call row.take() in build_from_row

impl ToSql<Hstore, Pg> for Hstore

fn to_sql<W>(
    &self,
    out: &mut ToSqlOutput<W, Pg>
) -> Result<IsNull, Box<StdError + Send + Sync>> where
    W: Write, 

impl Debug for Hstore

fn fmt(&self, __arg_0: &mut Formatter) -> Result

Formats the value using the given formatter.

impl Clone for Hstore

fn clone(&self) -> Hstore

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Default for Hstore

fn default() -> Hstore

Returns the "default value" for a type.

impl PartialEq for Hstore

fn eq(&self, __arg_0: &Hstore) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, __arg_0: &Hstore) -> bool

This method tests for !=.

impl Eq for Hstore

impl Deref for Hstore

You can deref the Hstore into it's backing HashMap

use diesel_pg_hstore::Hstore;
use std::collections::HashMap;

let mut settings = Hstore::new();
settings.insert("Hello".into(), "World".into());
let hashmap: &HashMap<String, String> = &*settings;

type Target = HashMap<String, String>

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl DerefMut for Hstore

You can mutably deref the Hstore into it's backing HashMap

use diesel_pg_hstore::Hstore;
use std::collections::HashMap;

let mut settings = Hstore::new();
settings.insert("Hello".into(), "World".into());
let mut hashmap: &mut HashMap<String, String> = &mut *settings;

fn deref_mut(&mut self) -> &mut HashMap<String, String>

Mutably dereferences the value.

impl IntoIterator for Hstore

type Item = (String, String)

The type of the elements being iterated over.

type IntoIter = IntoIter<String, String>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<'a> IntoIterator for &'a Hstore

type Item = (&'a String, &'a String)

The type of the elements being iterated over.

type IntoIter = Iter<'a, String, String>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<'a> IntoIterator for &'a mut Hstore

type Item = (&'a String, &'a mut String)

The type of the elements being iterated over.

type IntoIter = IterMut<'a, String, String>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl FromIterator<(String, String)> for Hstore

fn from_iter<T>(iter: T) -> Hstore where
    T: IntoIterator<Item = (String, String)>, 

Creates a value from an iterator.

impl<'a> Index<&'a str> for Hstore

type Output = String

The returned type after indexing.

fn index(&self, index: &'a str) -> &Self::Output

Performs the indexing (container[index]) operation.

impl Extend<(String, String)> for Hstore

fn extend<T>(&mut self, iter: T) where
    T: IntoIterator<Item = (String, String)>, 

Extends a collection with the contents of an iterator.