Fast Unicode validation and transcoding - development files

 Most modern software relies on the Unicode standard. In memory, Unicode
 strings are represented using either UTF-8 or UTF-16. The UTF-8 format is the
 de facto standard on the web (JSON, HTML, etc.) and it has been adopted as the
 default in many popular programming languages (Go, Zig, Rust, Swift, etc.).
 The UTF-16 format is standard in Java, C# and in many Windows technologies.
 .
 Not all sequences of bytes are valid Unicode strings. It is unsafe to use
 Unicode strings in UTF-8 and UTF-16LE without first validating them.
 Furthermore, we often need to convert strings from one encoding to another, by
 a process called transcoding. For security purposes, such transcoding should
 be validating: it should refuse to transcode incorrect strings.
 .
 This library provide fast Unicode functions such as
 .
  * ASCII, UTF-8, UTF-16LE/BE and UTF-32 validation, with and without error
    identification,
  * Latin1 to UTF-8 transcoding,
  * Latin1 to UTF-16LE/BE transcoding
  * Latin1 to UTF-32 transcoding
  * UTF-8 to Latin1 transcoding, with or without validation, with and without
    error identification,
  * UTF-8 to UTF-16LE/BE transcoding, with or without validation, with and
    without error identification,
  * UTF-8 to UTF-32 transcoding, with or without validation, with and without
    error identification,
  * UTF-16LE/BE to Latin1 transcoding, with or without validation, with and
    without error identification,
  * UTF-16LE/BE to UTF-8 transcoding, with or without validation, with and
    without error identification,
  * UTF-32 to Latin1 transcoding, with or without validation, with and without
    error identification,
  * UTF-32 to UTF-8 transcoding, with or without validation, with and without
    error identification,
  * UTF-32 to UTF-16LE/BE transcoding, with or without validation, with and
    without error identification,
  * UTF-16LE/BE to UTF-32 transcoding, with or without validation, with and
    without error identification,
  * From an UTF-8 string, compute the size of the Latin1 equivalent string,
  * From an UTF-8 string, compute the size of the UTF-16 equivalent string,
  * From an UTF-8 string, compute the size of the UTF-32 equivalent string
    (equivalent to UTF-8 character counting),
  * From an UTF-16LE/BE string, compute the size of the Latin1 equivalent
    string,
  * From an UTF-16LE/BE string, compute the size of the UTF-8 equivalent
    string,
  * From an UTF-32 string, compute the size of the UTF-8 or UTF-16LE equivalent
    string,
  * From an UTF-16LE/BE string, compute the size of the UTF-32 equivalent
    string (equivalent to UTF-16 character counting),
  * UTF-8 and UTF-16LE/BE character counting,
  * UTF-16 endianness change (UTF16-LE/BE to UTF-16-BE/LE),
  * WHATWG forgiving-base64 (with or without URL encoding) to binary,
  * Binary to base64 (with or without URL encoding).
 .
 The functions are accelerated using SIMD instructions (e.g., ARM NEON, SSE,
 AVX, AVX-512, RISC-V Vector Extension, LoongSon, POWER, etc.). When your
 strings contain hundreds of characters, we can often transcode them at speeds
 exceeding a billion characters per second. You should expect high speeds not
 only with English strings (ASCII) but also Chinese, Japanese, Arabic, and so
 forth. We handle the full character range (including, for example, emojis).
 .
 The library compiles down to a small library of a few hundred kilobytes. Our
 functions are exception-free and non allocating. We have extensive tests and
 extensive benchmarks.
 .
 This package ships the development files.