cli::ParseResult< T > Struct Template Reference

The result returned by Parser::parse() and the free cli::parse() function. More...

#include <parser.hh>

Public Member Functions
constexpr	operator bool () const noexcept
	Returns true when parsing succeeded.
constexpr auto	has_value () const noexcept -> bool
	Returns true when parsing succeeded.
constexpr auto	has_error () const noexcept -> bool
	Returns true when parsing failed.

Static Public Member Functions
template<class U>
static constexpr auto	ok (U &&value) -> ParseResult< T >
	Creates a success result holding value.
static constexpr auto	fail (ParseError error) -> ParseResult< T >
	Creates a failure result carrying error.

Public Attributes
T	value {}
	The parsed argument struct (valid only when has_value() is true).
ParseError	error {}
	The error details (valid only when has_error() is true).

Detailed Description

template<class T>
struct cli::ParseResult< T >

The result returned by Parser::parse() and the free cli::parse() function.

On success, value holds the fully populated argument specification struct and error is in the default (no-error) state. On failure, error describes what went wrong and value is in a partially-initialised (unusable) state.

Typical usage:

auto result = cli::parse<MyArgs>(argc, argv);
if (!result) {
    std::cerr << result.error.message() << '\n';
    return 1;
}
// use result.value …

Template Parameters

T	The argument specification type.

Definition at line 661 of file parser.hh.

Member Function Documentation

fail()

template<class T>

constexpr auto cli::ParseResult< T >::fail ( ParseError error ) -> ParseResult< T >

inlinestaticnodiscardconstexpr

Creates a failure result carrying error.

Parameters

error

The error to store.

Returns

A failed ParseResult<T>.

Definition at line 708 of file parser.hh.

has_error()

template<class T>

auto cli::ParseResult< T >::has_error ( ) const -> bool

inlinenodiscardconstexprnoexcept

Returns true when parsing failed.

Definition at line 681 of file parser.hh.

has_value()

template<class T>

auto cli::ParseResult< T >::has_value ( ) const -> bool

inlinenodiscardconstexprnoexcept

Returns true when parsing succeeded.

Definition at line 675 of file parser.hh.

ok()

template<class T>

template<class U>

constexpr auto cli::ParseResult< T >::ok ( U && value ) -> ParseResult< T >

inlinestaticnodiscardconstexpr

Creates a success result holding value.

Template Parameters

U	Type of the value (deduced).

Parameters

value

The parsed argument struct to store.

Returns

A successful ParseResult<T>.

Definition at line 694 of file parser.hh.

operator bool()

template<class T>

cli::ParseResult< T >::operator bool ( ) const

inlineexplicitnodiscardconstexprnoexcept

Returns true when parsing succeeded.

Definition at line 669 of file parser.hh.

Member Data Documentation

error

template<class T>

ParseError cli::ParseResult< T >::error {}

The error details (valid only when has_error() is true).

Definition at line 665 of file parser.hh.

value

template<class T>

T cli::ParseResult< T >::value {}

The parsed argument struct (valid only when has_value() is true).

Definition at line 662 of file parser.hh.

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

• include/cli/parser.hh