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doc/features.md

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+# RapidJSON Features
+
+## General
+
+* Cross-platform
+ * Compiler: tested Visual Studio, gcc, clang
+ * Architecture: x86, x64, ARM
+ * Operating systems: Windows, Mac OS X, Linux, iOS, Android
+* Easy installation
+ * Header files only library. Just copy the headers to your project.
+* Self-contained, minimal dependence
+ * No STL, BOOST, etc.
+ * Only included `<cstdio>`, `<cstdlib>`, `<cstring>`, `<inttypes.h>`, `<new>`, `<stdint.h>`.
+* High performance
+ * Use template and inline functions to reduce function call overheads.
+ * Optional SSE2/SSE4.1 support.
+
+## Standard compliance
+
+* RapidJSON should be fully RFC4627/ECMA-404 compliance.
+* Support unicode surrogate.
+* Support null character (`"\u0000"`)
+** For example, `["Hello\u0000World"]` can be parsed and handled gracefully.
+
+## API style
+
+* SAX (Simple API for XML) style API
+ * Similar to [SAX](http://en.wikipedia.org/wiki/Simple_API_for_XML), RapidJSON provides a event sequential access parser API (`GenericReader`). It also provides a generator API (`GenericWriter`) which consumes the same set of events.
+* DOM (Document Object Model) style API
+ * Similar to [DOM](http://en.wikipedia.org/wiki/Document_Object_Model) for HTML/XML, RapidJSON can parse JSON into a DOM representation (`GenericDocument`), for easy manipulation, and finally stringify back to JSON if needed.
+ * The DOM style API (`GenericDocument`) is actually implemented with SAX style API (`GenericReader`). SAX is faster but sometimes DOM is easier. Users can pick their choices according to scenarios.
+
+## Unicode
+
+* Support UTF-8, UTF-16, UTF-32 encodings, including little endian and big endian.
+ * These encodings are used in input/output streams and in-memory representation.
+* Support transcoding between encodings internally.
+ * For example, you can read a UTF-8 file and let RapidJSON transcode the JSON strings into UTF-16 in the DOM.
+* Support encoding validation internally.
+ * For example, you can read a UTF-8 file, and let RapidJSON check whether all JSON strings are valid UTF-8 byte sequence.
+* Support custom encodings.
+
+## Stream
+
+* Support `GenericStringBuffer` for storing the output JSON as string.
+* Support `FileReadStream`/`FileWriteStream` for input/output `FILE` object.
+* Support custom streams.
+
+## JSON formatting
+
+* Support PrettyWriter for adding newlines and indentations.
+
+## Memory
+
+* Minimize memory overheads for DOM.
+ * Each JSON value occupies exactly 16/20 bytes for most 32/64-bit machines (excluding text string).
+* Support fast default allocator.
+ * A stack-based allocator (allocate sequentially, prohibit to free individual allocations, suitable for parsing).
+ * User can provide a pre-allocated buffer. (Possible to parse a number of JSONs without any CRT allocation)
+* Standard CRT(C-runtime) allocator.
+* Support custom allocators.