eosio::singleton

Module: Contracts API / Singleton Table

More...

#include <singleton.hpp>

Public Functions

	Name
	singleton(name code, uint64_t scope)
bool	exists()
T	get() Get the value stored inside the singleton table.
T	get_or_default(const T & def =T())
T	get_or_create(name bill_to_account, const T & def =T())
void	set(const T & value, name bill_to_account)
void	remove()

Detailed Description

template <name::raw SingletonName,
typename T >
class eosio::singleton;

Template Parameters:

• SingletonName - the name of this singleton variable
• T - the type of the singleton

This wrapper uses a single table to store named objects various types.

Public Functions Documentation

function singleton

inline singleton(
    name code,
    uint64_t scope
)

Parameters:

• code - The table's owner
• scope - The scope of the table

Construct a new singleton object given the table's owner and the scope

function exists

inline bool exists()

Return:

• true - if exists
• false - otherwise

Check if the singleton table exists

function get

inline T get()

Get the value stored inside the singleton table.

Return: T - The value stored

Get the value stored inside the singleton table. Will throw an exception if it doesn't exist

function get_or_default

inline T get_or_default(
    const T & def =T()
)

Parameters:

• def - The default value to be returned in case the data doesn't exist

Return: T - The value stored

Get the value stored inside the singleton table. If it doesn't exist, it will return the specified default value

function get_or_create

inline T get_or_create(
    name bill_to_account,
    const T & def =T()
)

Parameters:

• bill_to_account - The account to bill for the newly created data if the data doesn't exist
• def - The default value to be created in case the data doesn't exist

Return: T - The value stored

Get the value stored inside the singleton table. If it doesn't exist, it will create a new one with the specified default value

function set

inline void set(
    const T & value,
    name bill_to_account
)

Parameters:

• value - New value to be set
• bill_to_account - Account to pay for the new value

Set new value to the singleton table

function remove

inline void remove()

Remove the only data inside singleton table

---

Updated on 2022-12-05 at 15:38:07 +0000