Conditional Macro Declaration

[marcioAlmada]

The idea is to use a ·requires tag that must be evaluated before the macro "compilation". Macro will be skipped in case the expression is false:

macro ·requires(version_compare(PHP_VERSION, '7.1.0', '>')) {
    /* some match that depends on a PHP 7.1+ token */
} >> {
    /* the macro implementation */
}