A base class for Keys. More...

#include <IMP/kernel/Key.h>

Inheritance diagram for IMP::kernel::Key< ID, LazyAdd >:

Public Member Functions
	Key ()
	make a default key in a well-defined null state

	Key (std::string c)
	Generate a key from the given string. More...

unsigned int	get_index () const

const std::string	get_string () const
	Turn a key into a pretty string.

Key	operator+ (int o) const

Key &	operator++ ()

Key &	operator-- ()

void	show (std::ostream &out=std::cout) const

Static Public Member Functions
static Key< ID, LazyAdd >	add_alias (Key< ID, LazyAdd > old_key, std::string new_name)
	Make new_name an alias for old_key. More...

static unsigned int	add_key (std::string sc)

static base::Vector< std::string >	get_all_strings ()
	Get a list of all of the keys of this type. More...

static bool	get_key_exists (std::string sc)
	Return true if there already is a key with that string.

static unsigned int	get_number_unique ()
	Get the total number of keys of this type. More...

static void	show_all (std::ostream &out)
	Show all the keys of this type.

Detailed Description

template<unsigned int ID, bool LazyAdd>
class IMP::kernel::Key< ID, LazyAdd >

This class does internal caching of the strings to accelerate the name lookup. It is better to create a Key and reuse it rather than recreate it many times from strings.

If you use this with a new type, you must add a new definition of attribute_table_index. Yes, this is an evil hack, but I couldn't get linking to work with static members of the template class.

The keys in IMP maintain a cached mapping between strings and indexes. This mapping is global–that is all IMP Models and Particles in the same program use the same mapping for each type of key. The type of the key is determined by an integer which should be unique for each type. If the integer is not unique, everything works, just more memory is wasted and types are interconvertible.

Keys used for storing attributes in particles should never be statically initialized. While this is annoying, statically initializing them is bad, as unused attribute keys can result in wasted memory in each particle.

If LazyAdd is true, keys created with a new string will be added, otherwise this is an error.

Definition at line 46 of file kernel/Key.h.