sharg::value_list_validator< option_value_t > Class Template Reference

A validator that checks whether a value is inside a list of valid values. More...

#include <sharg/validators.hpp>

Inheritance diagram for sharg::value_list_validator< option_value_t >:

Public Types
using	option_value_type = option_value_t
	Type of values that are tested by validator.

Public Member Functions
void	operator() (option_value_type const &cmp) const
	Tests whether cmp lies inside values. More...
template<std::ranges::forward_range range_type> requires std::convertible_to<std::ranges::range_value_t<range_type>, option_value_type> && (!std::same_as<std::remove_cvref_t<range_type>, std::filesystem::path>)
void	operator() (range_type const &range) const
	Tests whether every element in range lies inside values. More...
std::string	get_help_page_message () const
	Returns a message that can be appended to the (positional) options help page info. More...
Constructors, destructor and assignment
	value_list_validator ()=default
	Defaulted.
	value_list_validator (value_list_validator const &)=default
	Defaulted.
	value_list_validator (value_list_validator &&)=default
	Defaulted.
value_list_validator &	operator= (value_list_validator const &)=default
	Defaulted.
value_list_validator &	operator= (value_list_validator &&)=default
	Defaulted.
	~value_list_validator ()=default
	Defaulted.
template<std::ranges::forward_range range_type> requires std::constructible_from<option_value_type, std::ranges::range_rvalue_reference_t<range_type>>
	value_list_validator (range_type rng)
	Constructing from a range. More...
template<typename... option_types> requires ((std::constructible_from<option_value_type, option_types> && ...))
	value_list_validator (option_types &&... opts)
	Constructing from a parameter pack. More...

Related Functions
(Note that these are not member functions.)
Type deduction guides
template<typename option_type , typename... option_types>
	value_list_validator (option_type, option_types...) -> value_list_validator< std::string >
	Given a parameter pack of types that are convertible to std::string, delegate to value type std::string.
template<typename range_type >
	value_list_validator (range_type &&rng) -> value_list_validator< std::string >
	Deduction guide for ranges over a value type convertible to std::string.
template<typename option_type , typename... option_types>
	value_list_validator (option_type, option_types...) -> value_list_validator< option_type >
	Deduction guide for a parameter pack.
template<typename range_type >
	value_list_validator (range_type &&rng) -> value_list_validator< std::ranges::range_value_t< range_type > >
	Deduction guide for ranges.

Detailed Description

template<parsable option_value_t>
class sharg::value_list_validator< option_value_t >

A validator that checks whether a value is inside a list of valid values.

Template Parameters

option_value_t

The type the validator is called on. Must model sharg::parsable.

On construction, the validator must receive a range or parameter pack of valid values. The class then acts as a functor that throws a sharg::validation_error exception whenever a given value is not in the list.

Note

In order to simplify the chaining of validators, the option value type is deduced to std::string if the range's value type is convertible to it. Otherwise, the option value type is deduced to the value type of the range.

#include <sharg/all.hpp>
 
int main(int argc, char const ** argv)
{
    sharg::parser myparser{"Test", argc, argv}; // initialize
 
    int myint;
    sharg::value_list_validator my_validator{2, 4, 6, 8, 10};
 
    myparser.add_option(myint,
                        sharg::config{.short_id = 'i',
                                      .long_id = "integer",
                                      .description = "Give me a number.",
                                      .validator = my_validator});
 
    // an exception will be thrown if the user specifies an integer
    // that is not one of [2,4,6,8,10] (e.g. "./test_app -i 3")
    try
    {
        myparser.parse();
    }
    catch (sharg::parser_error const & ext) // the user did something wrong
    {
        std::cerr << "[PARSER ERROR] " << ext.what() << "\n"; // customize your error message
        return -1;
    }
 
    std::cerr << "integer given by user passed validation: " << myint << "\n";
    return 0;
}

Remarks

For a complete overview, take a look at Parser

This entity is stable. Since version 1.0.

Constructor & Destructor Documentation

value_list_validator() [1/2] [stable-api]

template<parsable option_value_t>

template<std::ranges::forward_range range_type>
requires std::constructible_from<option_value_type, std::ranges::range_rvalue_reference_t<range_type>>

sharg::value_list_validator< option_value_t >::value_list_validator ( range_type  rng )

stable-apiinline

Constructing from a range.

Template Parameters

range_type

The type of range; must model std::ranges::forward_range and value_list_validator::option_value_type must be constructible from the rvalue reference type of the given range.

Parameters

[in]

rng

The range of valid values to test.

This entity is stable. Since version 1.0.

value_list_validator() [2/2] [stable-api]

template<parsable option_value_t>

template<typename... option_types>
requires ((std::constructible_from<option_value_type, option_types> && ...))

sharg::value_list_validator< option_value_t >::value_list_validator ( option_types &&...  opts )

stable-apiinline

Constructing from a parameter pack.

Template Parameters

option_types

The type of option values in the parameter pack; The value_list_validator::option_value_type must be constructible from each type in the parameter pack.

Parameters

[in]

opts

The parameter pack values.

This entity is stable. Since version 1.0.

Member Function Documentation

get_help_page_message() [stable-api]

template<parsable option_value_t>

std::string sharg::value_list_validator< option_value_t >::get_help_page_message ( ) const

stable-apiinline

Returns a message that can be appended to the (positional) options help page info.

This entity is stable. Since version 1.0.

operator()() [1/2] [stable-api]

template<parsable option_value_t>

void sharg::value_list_validator< option_value_t >::operator() ( option_value_type const &  cmp ) const

stable-apiinline

Tests whether cmp lies inside values.

Parameters

cmp	The input value to check.

Exceptions

sharg::validation_error

This entity is stable. Since version 1.0.

operator()() [2/2] [stable-api]

template<parsable option_value_t>

template<std::ranges::forward_range range_type>
requires std::convertible_to<std::ranges::range_value_t<range_type>, option_value_type> && (!std::same_as<std::remove_cvref_t<range_type>, std::filesystem::path>)

void sharg::value_list_validator< option_value_t >::operator() ( range_type const &  range ) const

stable-apiinline

Tests whether every element in range lies inside values.

Template Parameters

range_type

The type of range to check; must model std::ranges::forward_range.

Parameters

range

The input range to iterate over and check every element.

Exceptions

sharg::validation_error

This entity is stable. Since version 1.0.

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

• validators.hpp