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#pragma once
///@file
#include "types.hh"
#include "error.hh"
#include "logging.hh"
#include "ansicolor.hh"
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/resource.h>
#include <dirent.h>
#include <unistd.h>
#include <signal.h>
#include <boost/lexical_cast.hpp>
#include <atomic>
#include <functional>
#include <map>
#include <sstream>
#include <optional>
#ifndef HAVE_STRUCT_DIRENT_D_TYPE
#define DT_UNKNOWN 0
#define DT_REG 1
#define DT_LNK 2
#define DT_DIR 3
#endif
namespace nix {
struct Sink;
struct Source;
/**
* The system for which Nix is compiled.
*/
extern const std::string nativeSystem;
/**
* Exception handling in destructors: print an error message, then
* ignore the exception.
*/
void ignoreException(Verbosity lvl = lvlError);
/**
* Get a value for the specified key from an associate container.
*/
template <class T>
const typename T::mapped_type * get(const T & map, const typename T::key_type & key)
{
auto i = map.find(key);
if (i == map.end()) return nullptr;
return &i->second;
}
template <class T>
typename T::mapped_type * get(T & map, const typename T::key_type & key)
{
auto i = map.find(key);
if (i == map.end()) return nullptr;
return &i->second;
}
/**
* Get a value for the specified key from an associate container, or a default value if the key isn't present.
*/
template <class T>
const typename T::mapped_type & getOr(T & map,
const typename T::key_type & key,
const typename T::mapped_type & defaultValue)
{
auto i = map.find(key);
if (i == map.end()) return defaultValue;
return i->second;
}
/**
* Remove and return the first item from a container.
*/
template <class T>
std::optional<typename T::value_type> remove_begin(T & c)
{
auto i = c.begin();
if (i == c.end()) return {};
auto v = std::move(*i);
c.erase(i);
return v;
}
/**
* Remove and return the first item from a container.
*/
template <class T>
std::optional<typename T::value_type> pop(T & c)
{
if (c.empty()) return {};
auto v = std::move(c.front());
c.pop();
return v;
}
/**
* A RAII helper that increments a counter on construction and
* decrements it on destruction.
*/
template<typename T>
struct MaintainCount
{
T & counter;
long delta;
MaintainCount(T & counter, long delta = 1) : counter(counter), delta(delta) { counter += delta; }
~MaintainCount() { counter -= delta; }
};
/**
* A Rust/Python-like enumerate() iterator adapter.
*
* Borrowed from http://reedbeta.com/blog/python-like-enumerate-in-cpp17.
*/
template <typename T,
typename TIter = decltype(std::begin(std::declval<T>())),
typename = decltype(std::end(std::declval<T>()))>
constexpr auto enumerate(T && iterable)
{
struct iterator
{
size_t i;
TIter iter;
constexpr bool operator != (const iterator & other) const { return iter != other.iter; }
constexpr void operator ++ () { ++i; ++iter; }
constexpr auto operator * () const { return std::tie(i, *iter); }
};
struct iterable_wrapper
{
T iterable;
constexpr auto begin() { return iterator{ 0, std::begin(iterable) }; }
constexpr auto end() { return iterator{ 0, std::end(iterable) }; }
};
return iterable_wrapper{ std::forward<T>(iterable) };
}
/**
* C++17 std::visit boilerplate
*/
template<class... Ts> struct overloaded : Ts... { using Ts::operator()...; };
template<class... Ts> overloaded(Ts...) -> overloaded<Ts...>;
}
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