posts/urls-in-cpp.en.html

   1 <!-- subject: Pro tip: You can put {URLs} in {C} & {C++} code -->
   2 <!-- date: 2022-04-01 01:17:43 -->
   3 <!-- tags: c, c++ -->
   4 <!-- categories: Misc, Techblog -->
   5
   6 <p>Documenting source code is important part of software engineering.  Code is
   7   read more often than it’s written making it crucial to provide enough context
   8   for reader to understand what the implementation is doing.  This can come in
   9   the form of links to external resources providing description of an algorithm,
  10   reference for an API or historic context justifying the code.
  11
  12 <p>As it turns out, C and C++ languages offer a little-known feature which
  13   allows URLs to be included directly in the function source code.  For example:
  14
  15 <pre>
  16 static float rsqrt(float x) {
  17         <a href=https://en.wikipedia.org/wiki/Fast_inverse_square_root>https://en.wikipedia.org/wiki/Fast_inverse_square_root</a>
  18         static_assert(std::numeric_limits&lt;float>::is_iec559);
  19         auto i = std::bit_cast&lt;uint32_t>(x) >> 1;
  20         auto y = std::bit_cast&lt;float>(UINT32_C(0x5F375A86) - i);
  21         y *= 1.5f - x * 0.5F * y * y;
  22         return y;
  23 }
  24 </pre>