caf::config_value Class Reference

A type for config parameters with similar interface to a variant. More...

#include <config_value.hpp>

Public Types
using	integer = int64_t
using	boolean = bool
using	real = double
using	string = std::string
using	list = std::vector<config_value>
using	dictionary = caf::dictionary<config_value>
using	types
using	variant_type = detail::tl_apply_t<types, std::variant>

Public Member Functions
	config_value (config_value &&other)=default
	config_value (const config_value &other)=default
template<class T , class = std::enable_if_t< !std::is_same_v<std::decay_t<T>, config_value>>>
	config_value (T &&x)
config_value &	operator= (config_value &&other)=default
config_value &	operator= (const config_value &other)=default
template<class T , class = std::enable_if_t< !std::is_same_v<std::decay_t<T>, config_value>>>
config_value &	operator= (T &&x)
void	convert_to_list ()
	Converts the value to a list with one element (unless the config value holds nullptr).
list &	as_list ()
	Returns the value as a list, converting it to one if needed.
dictionary &	as_dictionary ()
	Returns the value as a dictionary, converting it to one if needed.
void	append (config_value x)
	Appends x to a list.
const char *	type_name () const noexcept
	Returns a human-readable type name of the current value.
	operator bool () const noexcept
	Checks whether this config value is not null.
bool	operator! () const noexcept
	Checks whether this config value is null.
template<class T >
error	assign (T &&x)

Static Public Member Functions
static expected< config_value >	parse (std::string_view::iterator first, std::string_view::iterator last)
	Tries to parse a value from given characters.
static expected< config_value >	parse (std::string_view str)
	Tries to parse a value from str.
template<class Handle >
static std::optional< message >	parse_msg (std::string_view str, const Handle &)
	Tries to parse a config value (list) from str and to convert it to an allowed input message type for Handle.
template<class T >
static constexpr std::string_view	mapped_type_name ()

Related Symbols
(Note that these are not member symbols.)
using	settings = dictionary<config_value>
	Software options stored as key-value pairs.
CAF_CORE_EXPORT std::string	to_string (const config_value &x)
template<class T >
expected< T >	get_as (const config_value &value)
	Converts a config_value to builtin types or user-defined types that opted into the type inspection API.
template<class To = get_or_auto_deduce, class Fallback >
auto	get_or (const config_value &x, Fallback &&fallback)
	Converts a config_value to To or returns fallback if the conversion fails.
CAF_CORE_EXPORT bool	operator< (const config_value &x, const config_value &y)
CAF_CORE_EXPORT bool	operator<= (const config_value &x, const config_value &y)
CAF_CORE_EXPORT bool	operator== (const config_value &x, const config_value &y)
CAF_CORE_EXPORT bool	operator> (const config_value &x, const config_value &y)
CAF_CORE_EXPORT bool	operator>= (const config_value &x, const config_value &y)
bool	operator!= (const config_value &x, const config_value &y)
CAF_CORE_EXPORT std::ostream &	operator<< (std::ostream &out, const config_value &x)
CAF_CORE_EXPORT std::string	to_string (const settings &xs)
CAF_CORE_EXPORT const config_value *	get_if (const settings *xs, std::string_view name)
	Tries to retrieve the value associated to name from xs.
template<class T >
auto	get_if (const settings *xs, std::string_view name)
	Tries to retrieve the value associated to name from xs.
template<class T >
bool	holds_alternative (const settings &xs, std::string_view name)
	Returns whether xs associates a value of type T to name.

Detailed Description

A type for config parameters with similar interface to a variant.

This type is not implemented as a simple variant alias because variants cannot contain lists of themselves.

Member Typedef Documentation

types

using caf::config_value::types

Initial value:

 type_list<none_t, integer, boolean, real, timespan, uri, string,
                          list, dictionary>

Member Function Documentation

append()

void caf::config_value::append

(

config_value

x

)

Appends x to a list.

Converts this config value to a list first by calling convert_to_list if needed.

as_dictionary()

config_value::dictionary & caf::config_value::as_dictionary

(

)

Returns the value as a dictionary, converting it to one if needed.

The only data structure that CAF can convert to a dictionary is a list of lists, where each nested list contains exactly two elements (key and value). In all other cases, the conversion results in an empty dictionary.

convert_to_list()

void caf::config_value::convert_to_list

(

)

Converts the value to a list with one element (unless the config value holds nullptr).

Does nothing if the value already is a list.

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The documentation for this class was generated from the following files:

• libcaf_core/caf/config_value.hpp
• libcaf_core/caf/settings.hpp
• libcaf_core/caf/config_value.cpp