Staticcheck 2026.2 has just been released, and unfortunately there is already a 2026.2.1 on its way to fix a false positive. Now would be a great time to give 2026.2 a spin and report any bugs and false positives of your own so they can be part of 2026.2.1.
![type Cache[K, V any] struct {
m sync.Map
}
// Get returns the result of new.
//
// If Get was called on k before and didn't return an error, Get will return the
// same value it returned from the previous call.
//
// If Get is called concurrently on the same k value, new might get called
// multiple times. All calls will return the same value or an error from new.
//
// The cache is evicted some time after k becomes unreachable.
func (c *Cache[K, V]) Get(k *K, new func() (*V, error)) (*V, error) {
p := weak.Make(k)
if cached, ok := c.m.Load(p); ok {
return cached.(*V), nil
}
v, err := new()
if err != nil {
return nil, err
}
if cached, loaded := c.m.LoadOrStore(p, v); loaded {
// We lost the race, return the cached value and discard ours.
return cached.(*V), nil
}
runtime.AddCleanup(k, c.evict, p)
return v, nil
}
func (c *Cache[K, V]) evict(p weak.Pointer[K]) {
c.m.Delete(p)
}](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:x2nsupeeo52oznrmplwapppl/bafkreieim4wanlcu5wlb34hzkw7xdhyihsx3buwtltvtnv2g3xqtngdgyu)
