/*

 *  unspcs.c:

 * 1998/08      made public                                     kmatsui

 *

 *   These texts are unportable ones, because the order of the evaluation is

 * unspecified.  Good preprocessor will warn at these texts even if the

 * results are valid.  Good preprocessor will also document the order of

 * evaluation and the behavior on invalid results.

 *   Note: Order of evaluation of sub-expressions (other than operands of &&,

 * ||, ? :) of #if expression is also unspecified.  The order, however, never

 * affects the result, because #if expression never cause side effect, so no

 * warning is necessary.  Precedence and grouping rules of operators are other

 * things than order of evaluation, and shall be obeyed by preprocessor.

 */

#include    "defs.h"

#define str( a)     # a

#define xstr( a)    str( a)

main( void)

{

/* s.1.1:   Order of evaluation of #, ## operators. */

#define MAKWIDESTR( s)  L ## # s

/*  Either of L"name"; or L# name; ("L#" is not a valid pp-token).  */

    assert( MAKWIDESTR( name)[ 0] == L'n');

/* s.1.2:   Order of evaluation of ## operators.    */

#define glue3( a, b, c)     a ## b ## c

/*  "1.a" or undefined, since .a is not a valid pp-token, while 1. and 1.a are

        valid pp-tokens.    */

    puts( xstr( glue3( 1, ., a)));

    return  0;

}