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util.hh: Move stuff to types.hh

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Change-Id: Ia852306a4b8aac6856dc42bc69e4b58b53a0d67c
This commit is contained in:
Tom Hubrecht 2024-05-28 16:24:19 +02:00
parent 74513483bc
commit d73c40ff3d
2 changed files with 111 additions and 108 deletions
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111
src/libutil/types.hh
View file

@ -4,6 +4,7 @@
#include "ref.hh" #include "ref.hh"
#include <list> #include <list>
#include <optional>
#include <set> #include <set>
#include <string> #include <string>
#include <limits> #include <limits>
@ -51,6 +52,116 @@ struct Explicit {
} }
}; };
/**
* 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...>;
/** /**
* This wants to be a little bit like rust's Cow type. * This wants to be a little bit like rust's Cow type.

108
src/libutil/util.hh
View file

@ -40,114 +40,6 @@ extern const std::string nativeSystem;
/**
* 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...>;
} }