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#pragma once
///@file
#include "comparator.hh"
#include "error.hh"
#include "json-utils.hh"
#include "types.hh"
namespace nix {
/**
* The list of available experimental features.
*
* If you update this, don’t forget to also change the map defining
* their string representation and documentation in the corresponding
* `.cc` file as well.
*/
enum struct ExperimentalFeature
{
CaDerivations,
ImpureDerivations,
Flakes,
NixCommand,
RecursiveNix,
NoUrlLiterals,
FetchClosure,
ReplFlake,
AutoAllocateUids,
Cgroups,
DiscardReferences,
DaemonTrustOverride,
DynamicDerivations,
ParseTomlTimestamps,
ReadOnlyLocalStore,
};
/**
* Just because writing `ExperimentalFeature::CaDerivations` is way too long
*/
using Xp = ExperimentalFeature;
/**
* Parse an experimental feature (enum value) from its name. Experimental
* feature flag names are hyphenated and do not contain spaces.
*/
const std::optional<ExperimentalFeature> parseExperimentalFeature(
const std::string_view & name);
/**
* Show the name of an experimental feature. This is the opposite of
* parseExperimentalFeature().
*/
std::string_view showExperimentalFeature(const ExperimentalFeature);
/**
* Compute the documentation of all experimental features.
*
* See `doc/manual` for how this information is used.
*/
nlohmann::json documentExperimentalFeatures();
/**
* Shorthand for `str << showExperimentalFeature(feature)`.
*/
std::ostream & operator<<(
std::ostream & str,
const ExperimentalFeature & feature);
/**
* Parse a set of strings to the corresponding set of experimental
* features, ignoring (but warning for) any unknown feature.
*/
std::set<ExperimentalFeature> parseFeatures(const std::set<std::string> &);
/**
* An experimental feature was required for some (experimental)
* operation, but was not enabled.
*/
class MissingExperimentalFeature : public Error
{
public:
/**
* The experimental feature that was required but not enabled.
*/
ExperimentalFeature missingFeature;
MissingExperimentalFeature(ExperimentalFeature missingFeature);
};
/**
* Semi-magic conversion to and from json.
* See the nlohmann/json readme for more details.
*/
void to_json(nlohmann::json &, const ExperimentalFeature &);
void from_json(const nlohmann::json &, ExperimentalFeature &);
/**
* It is always rendered as a string
*/
template<>
struct json_avoids_null<ExperimentalFeature> : std::true_type {};
}
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