2.2.9 Concatenated Strings

If single or double quote characters are used, then you also have the option, a la ANSI-C syntax, of implicitly concatenating a series of them together, with intervening white space ignored.

NB You cannot use directives to alter the string content. That is,

str = "foo" #ifdef LATER "bar" #endif ;

will result in a syntax error. The preprocessing directives are not carried out by the C preprocessor. However,

str = '"foo\n" #ifdef LATER " bar\n" #endif ';

Will work. It will enclose the `#ifdef LATER' and `#endif' in the string. But it may also wreak havoc with the definition processing directives. The hash characters in the first column should be disambiguated with an escape \ or join them with previous lines: "foo\n#ifdef LATER....