fix: forgot to include a file

linear-interpolation/src/to_vector.h

@@ -0,0 +1,24 @@
+#ifndef TO_VECTOR_H
+#define TO_VECTOR_H
+
+#include <ranges>
+#include <vector>
+
+template <std::ranges::range R>
+auto to_vector(R&& r) {
+    std::vector<std::ranges::range_value_t<R>> v;
+
+    // if we can get a size, reserve that much
+    if constexpr (requires { std::ranges::size(r); }) {
+        v.reserve(std::ranges::size(r));
+    }
+
+    // push all the elements
+    for (auto&& e : r) {
+        v.push_back(static_cast<decltype(e)&&>(e));
+    }
+
+    return v;
+}
+
+#endif