parseExperimentalFeature(): Initialize atomically

This commit is contained in:
Eelco Dolstra 2021-10-26 14:29:48 +02:00
parent 9ce84c64c5
commit 0d9e050ba7

View file

@ -1,4 +1,6 @@
#include "experimental-features.hh"
#include "util.hh"
#include "nlohmann/json.hpp"
namespace nix {
@ -14,17 +16,19 @@ std::map<ExperimentalFeature, std::string> stringifiedXpFeatures = {
const std::optional<ExperimentalFeature> parseExperimentalFeature(const std::string_view & name)
{
using ReverseXpMap = std::map<std::string_view, ExperimentalFeature>;
static ReverseXpMap * reverseXpMap;
if (!reverseXpMap) {
reverseXpMap = new ReverseXpMap{};
static auto reverseXpMap = []()
{
auto reverseXpMap = std::make_unique<ReverseXpMap>();
for (auto & [feature, name] : stringifiedXpFeatures)
(*reverseXpMap)[name] = feature;
}
return reverseXpMap;
}();
auto featureIter = reverseXpMap->find(name);
if (featureIter == reverseXpMap->end())
if (auto feature = get(*reverseXpMap, name))
return *feature;
else
return std::nullopt;
return {featureIter->second};
}
std::string_view showExperimentalFeature(const ExperimentalFeature feature)