kakoune/src/constexpr_utils.hh
Maxime Coste 99636c6230 Remove Vector returning split functions, use range adaptor
Do not allocate temporary vectors to store splitted data, use the
'split' range adaptor along with transform(unescape) to provide the
same feature with less allocations.
2017-12-06 17:18:44 +08:00

84 lines
2.2 KiB
C++

#ifndef constexpr_utils_hh_INCLUDED
#define constexpr_utils_hh_INCLUDED
#include <utility>
#include <initializer_list>
#include <stddef.h>
#include "array_view.hh"
namespace Kakoune
{
template<typename T, size_t N>
struct Array
{
constexpr size_t size() const { return N; }
constexpr const T& operator[](int i) const { return m_data[i]; }
constexpr const T* begin() const { return m_data; }
constexpr const T* end() const { return m_data+N; }
constexpr operator ArrayView<T>() { return {m_data, N}; }
constexpr operator ConstArrayView<T>() const { return {m_data, N}; }
T m_data[N];
};
template<typename T, size_t N, size_t... Indices>
constexpr Array<T, N> make_array(const T (&data)[N], std::index_sequence<Indices...>)
{
static_assert(sizeof...(Indices) == N, "size mismatch");
return {{data[Indices]...}};
}
template<typename T, size_t N>
constexpr Array<T, N> make_array(const T (&data)[N])
{
return make_array(data, std::make_index_sequence<N>());
}
template<typename T, size_t capacity>
struct ConstexprVector
{
using iterator = T*;
using const_iterator = const T*;
constexpr ConstexprVector() : m_size{0} {}
constexpr ConstexprVector(std::initializer_list<T> items)
: m_size{items.size()}
{
T* ptr = m_data;
for (auto& item : items)
*ptr++ = std::move(item);
}
constexpr bool empty() const { return m_size == 0; }
constexpr size_t size() const { return m_size; }
constexpr void resize(size_t n, const T& val = {})
{
if (n >= capacity)
throw "capacity exceeded";
for (int i = m_size; i < n; ++i)
m_data[i] = val;
m_size = n;
kak_assert(this->size() == m_size); // check for https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79520
}
constexpr T& operator[](size_t i) { return m_data[i]; }
constexpr const T& operator[](size_t i) const { return m_data[i]; }
constexpr iterator begin() { return m_data; }
constexpr iterator end() { return m_data + m_size; }
constexpr const_iterator begin() const { return m_data; }
constexpr const_iterator end() const { return m_data + m_size; }
size_t m_size;
T m_data[capacity] = {};
};
}
#endif // constexpr_utils_hh_INCLUDED