Move OrSuggestions to its own header

Prevents a recursive inclusion
This commit is contained in:
regnat 2022-03-04 13:42:43 +01:00
parent b44cebd1fd
commit fd45d85b41
3 changed files with 65 additions and 59 deletions

View file

@ -3,6 +3,7 @@
#include "sync.hh" #include "sync.hh"
#include "hash.hh" #include "hash.hh"
#include "eval.hh" #include "eval.hh"
#include "or-suggestions.hh"
#include <functional> #include <functional>
#include <variant> #include <variant>

View file

@ -0,0 +1,64 @@
#include "suggestions.hh"
#include "error.hh"
namespace nix {
// Either a value of type `T`, or some suggestions
template<typename T>
class OrSuggestions {
public:
using Raw = std::variant<T, Suggestions>;
Raw raw;
T* operator ->()
{
return &**this;
}
T& operator *()
{
if (auto elt = std::get_if<T>(&raw))
return *elt;
throw Error("Invalid access to a failed value");
}
operator bool() const noexcept
{
return std::holds_alternative<T>(raw);
}
OrSuggestions(T t)
: raw(t)
{
}
OrSuggestions()
: raw(Suggestions{})
{
}
static OrSuggestions<T> failed(const Suggestions & s)
{
auto res = OrSuggestions<T>();
res.raw = s;
return res;
}
static OrSuggestions<T> failed()
{
return OrSuggestions<T>::failed(Suggestions{});
}
const Suggestions & getSuggestions()
{
static Suggestions noSuggestions;
if (const auto & suggestions = std::get_if<Suggestions>(&raw))
return *suggestions;
else
return noSuggestions;
}
};
}

View file

@ -39,63 +39,4 @@ public:
Suggestions& operator+=(const Suggestions & other); Suggestions& operator+=(const Suggestions & other);
}; };
// Either a value of type `T`, or some suggestions
template<typename T>
class OrSuggestions {
public:
using Raw = std::variant<T, Suggestions>;
Raw raw;
T* operator ->()
{
return &**this;
}
T& operator *()
{
if (auto elt = std::get_if<T>(&raw))
return *elt;
throw Error("Invalid access to a failed value");
}
operator bool() const noexcept
{
return std::holds_alternative<T>(raw);
}
OrSuggestions(T t)
: raw(t)
{
}
OrSuggestions()
: raw(Suggestions{})
{
}
static OrSuggestions<T> failed(const Suggestions & s)
{
auto res = OrSuggestions<T>();
res.raw = s;
return res;
}
static OrSuggestions<T> failed()
{
return OrSuggestions<T>::failed(Suggestions{});
}
const Suggestions & get_suggestions()
{
static Suggestions noSuggestions;
if (const auto & suggestions = std::get_if<Suggestions>(&raw))
return *suggestions;
else
return noSuggestions;
}
};
} }