arg_router::multi_lang Namespace Reference

Classes
class	root_t
class	root_wrapper_t
class	translation

Typedefs
template<std::size_t I, typename... S>
using	string_selector = std::tuple_element_t< I, std::tuple< S... > >

Functions
string	iso_locale (std::string_view locale_name)
template<typename DefaultLanguageID , typename... SupportedLanguageIDs, typename RootFactory >
auto	root (std::string_view language_id, const RootFactory &f)
template<typename... SupportedISOLanguageCodes, typename Fn >
auto	root_wrapper (std::string_view iso_language, Fn &&f)

Detailed Description

Namespace for types and functions relating to runtime multi-language support.

Typedef Documentation

string_selector

template<std::size_t I, typename... S>

using arg_router::multi_lang::string_selector = typedef std::tuple_element_t<I, std::tuple<S...> >

A compile time string container that acts a drop-in replacement for compile_time_string by compile-time selection of an element.

Template Parameters

I	String index to use
S	Strings to contain

Definition at line 25 of file string_selector.hpp.

Function Documentation

iso_locale()

string arg_router::multi_lang::iso_locale ( std::string_view  locale_name )

inline

Converts a locale name (i.e. a string returned by std::locale) into a standardised language code format.

The most common locale formats are:

<Lowercase ISO 639-1 language>_<Uppercase ISO 3166 country>.<encoding>
<Lowercase ISO 639-1 language>-<Uppercase ISO 3166 country>
<Lowercase ISO 639-1 language>-<Initial uppercase ISO 15924 script>-<Uppercase ISO 3166 country>

This function will strip off the encoding if present, and change the dividing character to an underscore. For example:

iso_country_code("en-US") == "en_US"
iso_country_code("en_GB.UTF-8") == "en_GB"
iso_country_code("fr.UTF-8") == "fr"
iso_country_code("uz-Latn-UZ") == "uz_Latn_UZ"

An empty string in yields an empty string out.

Typically locale_name is under the SSO string size, so allocation doesn't occur.

Parameters

locale_name

Local name to standardise

Returns

Standardised locale name

Definition at line 35 of file iso_locale.hpp.

root()

template<typename DefaultLanguageID , typename... SupportedLanguageIDs, typename RootFactory >

auto arg_router::multi_lang::root	(	std::string_view	language_id,
		const RootFactory &	f
	)

Convenience function that returns a root_t.

Allows the user to define the supported languages IDs in the template parameters but has Fn deduced from the input.

Template Parameters

DefaultLanguageID	The default language ID as a compile time string, this is used if the runtime input code does not match this or any of SupportedLanguageIDs
SupportedLanguageIDs	The supported language IDs as compile time strings
RootFactory	Function object type that accepts a multi_lang::translation specialisation and returns a root instance

Parameters

language_id	The runtime language selection, if it doesn't match any of the SupportedLanguageIDs, then DefaultLanguageID is used
f	Function object that returns the root instance for a given supported language

Returns

root_t instance

Definition at line 221 of file root.hpp.

root_wrapper()

template<typename... SupportedISOLanguageCodes, typename Fn >

auto arg_router::multi_lang::root_wrapper	(	std::string_view	iso_language,
		Fn &&	f
	)

Convenience function that returns a root_wrapper_t.

Allows the user to define the supported ISO languages in the template parameters but has Fn deduced from the input.

Parameters

iso_language	The runtime language selection, if it doesn't match any of SupportedISOLanguageCodes, then the first language in SupportedISOLanguageCodes is used
f	Function object that returns the root instance for a given supported language index

Returns

root_wrapper_t instance

Definition at line 153 of file root_wrapper.hpp.