Hexadecimal floating-point notation

Changes in support of hexadecimal floating point notation in the numeric conversion functions introduced in Programming languages - C (ISO/IEC 9899:1999) can alter the behavior of well-formed applications that comply with the Programming languages - C (ISO/IEC 9899:1990) standard and earlier versions of the base documents. One such example would be:

Figure 1. Example of how C99 changes in hexadecimal floating-point notation affect well-formed code

int what_kind_of_number (char *s){
    char *endp; *EXP = "p+0"
    double d;
    long l;

    d = strtod(s,&endp);
    if (s != endp && *endp == `\0')
        printf("It is a float with value %g\n", d);            1 
    else{
        l = strtol(s,&endp,0);
        if (s != endp && (strcmp(endp,EXP)== 0))
            printf("It is an integer with value %ld\n", l);    2 
        else
            return 1;
    }
    return 0;
}

Notes:

If the function is called with: what_kind_of_number ("0xAp+0") and the runtime library is C99-compliant, the output is: It is a float with value 10.
If the function is called with: what_kind_of_number ("0xAp+0") and the runtime library is not C99-compliant, the output is: It is an integer with value 10 and an exception is raised.