cache_anything.php

<?php

function get($thing, $reset = FALSE) {
  return cache_anything(__FUNC__, 'something_expensive', array($thing), $reset);
}

function get_something_else($other_thing, $reset = FALSE) {
  $slow = function ($other_thing) {
    // slow query with $other_thing
  };

  return cache_anything(__FUNC__, $slow, array($other_thing), $reset);
}

function cache_anything(string $cache_key, callable $func, array $args, bool $reset = FALSE) {
  $key = md5($cache_key . serialize($args));
  $cache = &drupal_static($key, NULL, $reset)
  if (!reset) $cache = call_user_func_array($func, $args);
  return $cache;
}

function something_expensive($thing) {
  // the slow, it burns!!
}