1 files changed, 78 insertions, 0 deletions
diff --git a/src/constexpr_utils.hh b/src/constexpr_utils.hh
new file mode 100644
index 00000000..f1d3ce81
--- /dev/null
+++ b/src/constexpr_utils.hh
@@ -0,0 +1,78 @@
+#ifndef constexpr_utils_hh_INCLUDED
+#define constexpr_utils_hh_INCLUDED
+
+#include <utility>
+#include <initializer_list>
+#include <stddef.h>
+
+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; }
+
+    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