feature: write indexed data to file.

src/output.hpp

@@ -0,0 +1,9 @@
+#include <array>
+#include <ostream>
+
+namespace wavefront {
+    template<typename NumericType>
+    void write_number(std::ostream &output, NumericType value) {
+        output.write(reinterpret_cast<char *>(&value), sizeof(NumericType));
+    }
+}