go-data-structures

Use make([]T, 0, n) for slices and make(map[K]V, n) for maps when the size is known or estimable. For bulk appends, slices.Grow (Go 1.21+) pre-grows capacity before the loop, eliminating repeated backing-array copies and map rehashing.

Use strings.Builder for pure string building because its String() method avoids a copy. Use bytes.Buffer when you need io.Reader/io.Writer interfaces or byte manipulation. Both support Grow(n) for preallocation.

Use container/list only for frequent middle insertions and removals, such as LRU caches needing O(1) move-to-front. Slices outperform linked lists for most cases due to cache locality, so benchmark before choosing a linked list.

No. Storing a pointer as uintptr across statements is dangerous because the GC can move the object between statements, leaving a dangling pointer. Keep values as typed pointers and use unsafe.Add or unsafe.Slice for arithmetic instead.

Store large structs as map[K]*V because map access copies the entire value per lookup. For small structs under roughly 128 bytes, value maps are typically faster since pointer maps add GC pressure.

weak.Pointer[T] (Go 1.24+) holds a reference without preventing garbage collection; Value() returns nil after the object is reclaimed. Use it for deduplication caches and canonicalization maps where entries should evict automatically.