The slowness of string eval (and headache of no compile-time catching of typos inside the eval) is not required here since we have constant code. I'd use:

    if(  my $got_GD= eval { require GD }  ) {
        GD->import();
    }
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Note that the import is done at run time (not compile time as would be the case with a use not inside eval), so you can't access your imported routines using barewords (you have to type the parentheses -- and, yes, I'm intentionally ignoring the use of &).

I often like to access imported (or predeclared) routines using barewords because it catches typos at compile time instead of only when that particular typo is executed (writing full coverage test suites is time consuming). But there are no good ways to do that with conditional importing (there are several ways, just none of them are good).