kakoune/src/utils.hh
Maxime Coste 993e842fdf Retreat ! go back to C++11 only code
This reverts commit b42de85031.
2015-05-26 18:42:09 +01:00

127 lines
2.3 KiB
C++

#ifndef utils_hh_INCLUDED
#define utils_hh_INCLUDED
#include "assert.hh"
#include <memory>
namespace Kakoune
{
template<typename T, typename... Args>
std::unique_ptr<T> make_unique(Args&&... args)
{
return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
}
template<size_t... I>
struct IndexSequence
{
using Next = IndexSequence<I..., sizeof...(I)>;
};
template<size_t N>
struct MakeIndexSequence
{
using Type = typename MakeIndexSequence<N-1>::Type::Next;
};
template<>
struct MakeIndexSequence<0>
{
using Type = IndexSequence<>;
};
template<size_t N>
constexpr typename MakeIndexSequence<N>::Type
make_index_sequence() { return typename MakeIndexSequence<N>::Type{}; }
// *** Singleton ***
//
// Singleton helper class, every singleton type T should inherit
// from Singleton<T> to provide a consistent interface.
template<typename T>
class Singleton
{
public:
Singleton(const Singleton&) = delete;
Singleton& operator=(const Singleton&) = delete;
static T& instance()
{
kak_assert (ms_instance);
return *ms_instance;
}
static bool has_instance()
{
return ms_instance != nullptr;
}
protected:
Singleton()
{
kak_assert(not ms_instance);
ms_instance = static_cast<T*>(this);
}
~Singleton()
{
kak_assert(ms_instance == this);
ms_instance = nullptr;
}
private:
static T* ms_instance;
};
template<typename T>
T* Singleton<T>::ms_instance = nullptr;
// *** On scope end ***
//
// on_scope_end provides a way to register some code to be
// executed when current scope closes.
//
// usage:
// auto cleaner = on_scope_end([]() { ... });
//
// This permits to cleanup c-style resources without implementing
// a wrapping class
template<typename T>
class OnScopeEnd
{
public:
[[gnu::always_inline]]
OnScopeEnd(T func) : m_func(std::move(func)) {}
[[gnu::always_inline]]
~OnScopeEnd() { m_func(); }
private:
T m_func;
};
template<typename T>
OnScopeEnd<T> on_scope_end(T t)
{
return OnScopeEnd<T>(t);
}
// *** Misc helper functions ***
template<typename T>
bool operator== (const std::unique_ptr<T>& lhs, T* rhs)
{
return lhs.get() == rhs;
}
template<typename T>
const T& clamp(const T& val, const T& min, const T& max)
{
return (val < min ? min : (val > max ? max : val));
}
}
#endif // utils_hh_INCLUDED