Double backslash in comment inside array

I have an array defined as follows:

extern const char config_reg[] = {  
  0x05, //comment
  0x00, //comment
  0x00, //  \\    <-- double backslash
  0x01, //comment
  0x03
}

As you can see, there is a double backslash inside a comment (the <-- double backslash and preceding spaces do not appear in the actual source file). When I compile this code (minus the "<-- double backslash") it acts as if the following line is non existent - i.e. equivalent to writing:

extern const char config_reg[] = {  
  0x05, //comment
  0x00, //comment
  0x00, //  

  0x03
}

Is this intended C++ behaviour? If so, what is its intended purpose?

I am compiling using the Parallax Propeller Simple IDE to compile my code - not a particularly good compiler, by all accounts. Is it likely that the compiler implementation is causing this behaviour?