cli::constraint Namespace Reference

Post-parse constraint helpers. More...

Functions
template<detail::NamedProviderArg... Args>
auto	one_of (const Args &... args) -> ConstraintResult
	Exactly one of the listed options must be provided.
template<detail::NamedProviderArg... Args>
auto	at_most_one_of (const Args &... args) -> ConstraintResult
	At most one of the listed options may be provided.
template<detail::NamedProviderArg... Args>
auto	all_of (const Args &... args) -> ConstraintResult
	All of the listed options must be provided.
template<detail::NamedProviderArg... Args>
auto	all_or_none (const Args &... args) -> ConstraintResult
	Either all of the listed options must be provided, or none.
template<detail::NamedProviderArg Cond, detail::NamedProviderArg Req>
auto	requires_if (const Cond &condition, const Req &required) -> ConstraintResult
	If condition is provided, required must also be provided.

Detailed Description

Post-parse constraint helpers.

Each function checks a relationship between options and returns a ConstraintResult. Combine results with && or ||:

auto constraints() -> cli::ConstraintResult {
  return cli::constraint::one_of(foo, bar)
      && cli::constraint::requires_if(output, format);
}

Function Documentation

all_of()

template<detail::NamedProviderArg... Args>

auto cli::constraint::all_of

(

const Args &...

args

)

-> ConstraintResult

All of the listed options must be provided.

Returns missing_required listing all names if any are absent.

Definition at line 137 of file constraint.hh.

all_or_none()

template<detail::NamedProviderArg... Args>

auto cli::constraint::all_or_none

(

const Args &...

args

)

-> ConstraintResult

Either all of the listed options must be provided, or none.

Returns dependency_missing when some but not all are present.

Definition at line 154 of file constraint.hh.

at_most_one_of()

template<detail::NamedProviderArg... Args>

auto cli::constraint::at_most_one_of

(

const Args &...

args

)

-> ConstraintResult

At most one of the listed options may be provided.

Returns mutually_exclusive if two or more are present simultaneously.

Definition at line 120 of file constraint.hh.

one_of()

template<detail::NamedProviderArg... Args>

auto cli::constraint::one_of

(

const Args &...

args

)

-> ConstraintResult

Exactly one of the listed options must be provided.

Returns validation_failed / mutually_exclusive with a message listing all option names when the count is 0 or ≥ 2.

Definition at line 93 of file constraint.hh.

requires_if()

template<detail::NamedProviderArg Cond, detail::NamedProviderArg Req>

auto cli::constraint::requires_if	(	const Cond &	condition,
		const Req &	required ) -> ConstraintResult

If condition is provided, required must also be provided.

Returns dependency_missing naming the missing option when the condition holds but the dependency is absent.

Definition at line 173 of file constraint.hh.