title: What exactly is the L prefix in C++?
body: <p>I understand what it does: specifies a string literal as a <code>const wchar_t *</code> (wide character string) instead of <code>const char *</code> (plain old characters), but how is it actually defined?</p>
  
  <p>Is it a macro of some sort? Is it an operator for GCC compilers? What <em>is</em> it?</p>