MapAccess.h File Reference

#include <cassert>
#include <type_traits>
#include <unordered_map>

Functions
template<class Map , class Key , class Value = typename Map::mapped_type>
Value	valueOr (const Map &map, const Key &key, const std::type_identity_t< Value > &def=Value())
template<class Map , class Key >
auto *	valuePtr (Map &&map, const Key &key)
template<class Key , class Value >
std::unordered_map< Value, Key >	inverted (const std::unordered_map< Key, Value > &map)

Function Documentation

inverted()

template<class Key , class Value >

std::unordered_map< Value, Key > inverted

(

const std::unordered_map< Key, Value > &

map

)

Inverts an unordered map, creating a map from values into keys.

The values must be unique, otherwise the function will assert.

Parameters

map	Map to invert.

Returns

Inverted map.

valueOr()

template<class Map , class Key , class Value = typename Map::mapped_type>

Value valueOr	(	const Map &	map,
		const Key &	key,
		const std::type_identity_t< Value > &	def = Value()
	)

Convenient map accessor that returns either the value stored in a map, or default value if the key doesn't exist.

Parameters

map	Map to get value from.
key	Key to look up value for.
def	Default value to return if the key is not in the map.

Returns

Value for the provided key, or def if the key was not found in the map.

valuePtr()

template<class Map , class Key >

auto * valuePtr	(	Map &&	map,
		const Key &	key
	)

Convenient map accessor that returns either the pointer to the value stored in a map, or nullptr if the key doesn't exist.

Parameters

map	Map to get value from.
key	Key to look up value for.

Returns

Pointer to the value for the provided key, or nullptr if the key was not found in the map.