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Merged
merged 1 commit into from
Sep 15, 2025
+13 −10
Merged

More get / getOr improvements #13999

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23 changes: 13 additions & 10 deletions src/libutil/include/nix/util/util.hh
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Original file line number Diff line number Diff line change
Expand Up @@ -197,7 +197,7 @@ std::pair<std::string_view, std::string_view> getLine(std::string_view s);
* Get a value for the specified key from an associate container.
*/
template<class T, typename K>
const typename T::mapped_type * get(const T & map, K & key)
const typename T::mapped_type * get(const T & map, const K & key)
{
auto i = map.find(key);
if (i == map.end())
Expand All @@ -206,34 +206,37 @@ const typename T::mapped_type * get(const T & map, K & key)
}

template<class T, typename K>
typename T::mapped_type * get(T & map, K & key)
typename T::mapped_type * get(T & map, const K & key)
{
auto i = map.find(key);
if (i == map.end())
return nullptr;
return &i->second;
}

/** Deleted because this is use-after-free liability. Just don't pass temporaries to this overload set. */
template<class T>
typename T::mapped_type * get(T && map, const typename T::key_type & key) = delete;
/**
* Deleted because this is use-after-free liability. Just don't pass temporaries to this overload set.
*/
template<class T, typename K>
typename T::mapped_type * get(T && map, const K & key) = delete;

/**
* Get a value for the specified key from an associate container, or a default value if the key isn't present.
*/
template<class T, typename K>
const typename T::mapped_type & getOr(T & map, K & key, const typename T::mapped_type & defaultValue)
const typename T::mapped_type & getOr(T & map, const K & key, const typename T::mapped_type & defaultValue)
{
auto i = map.find(key);
if (i == map.end())
return defaultValue;
return i->second;
}

/** Deleted because this is use-after-free liability. Just don't pass temporaries to this overload set. */
template<class T>
const typename T::mapped_type &
getOr(T && map, const typename T::key_type & key, const typename T::mapped_type & defaultValue) = delete;
/**
* Deleted because this is use-after-free liability. Just don't pass temporaries to this overload set.
*/
template<class T, typename K>
const typename T::mapped_type & getOr(T && map, const K & key, const typename T::mapped_type & defaultValue) = delete;

/**
* Remove and return the first item from a container.
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