Update README.rst
diff --git a/README.rst b/README.rst
index 9f5e543..5b35842 100644
--- a/README.rst
+++ b/README.rst
@@ -132,6 +132,19 @@
This gives a compile-time error because ``d`` is an invalid format specifier for
a string.
+Write a file from a single thread:
+
+.. code:: c++
+
+ #include <fmt/os.h>
+
+ int main() {
+ auto out = fmt::output_file("guide.txt");
+ out.print("Don't {}", "Panic");
+ }
+
+This is up to 6x faster than using ``printf``.
+
Create your own functions similar to `format
<https://fmt.dev/latest/api.html#format>`_ and
`print <https://fmt.dev/latest/api.html#print>`_