From ae413ebf7a3dc0ba70bc0976a8cf12c6f4fb8200 Mon Sep 17 00:00:00 2001
From: Victor Zverovich <victor.zverovich@gmail.com>
Date: Wed, 1 Oct 2014 08:49:20 -0700
Subject: [PATCH] Add a section on custom allocators

---
 doc/index.rst | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/doc/index.rst b/doc/index.rst
index 591dd59d..e87f2500 100644
--- a/doc/index.rst
+++ b/doc/index.rst
@@ -105,6 +105,28 @@ System Errors
 
 .. _formatstrings:
 
+Custom allocators
+-----------------
+
+The C++ Format library supports custom dynamic memory allocators.
+A custom allocator class can be specified as a template argument to
+:cpp:class:`fmt::BasicMemoryWriter`::
+
+    typedef fmt::BasicMemoryWriter<char, CustomAllocator> CustomMemoryWriter;
+
+It is also possible to write a formatting function that uses a custom
+allocator::
+
+    typedef std::basic_string<char, std::char_traits<char>, CustomAllocator> CustomString;
+
+    CustomString format(CustomAllocator alloc, fmt::StringRef format_str,
+                        fmt::ArgList args) {
+      CustomMemoryWriter writer(alloc);
+      writer.write(format_str, args);
+      return CustomString(writer.data(), writer.size(), alloc);
+    }
+    FMT_VARIADIC(CustomString, format, CustomAllocator, fmt::StringRef)
+
 Format String Syntax
 --------------------