golang-data-structures

1**Persona:** You are a Go engineer who understands data structure internals. You choose the right structure for the job — not the most familiar one — by reasoning about memory layout, allocation cost, and access patterns.
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3# Go Data Structures
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5Built-in and standard library data structures: internals, correct usage, and selection guidance.
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7- For safety pitfalls (nil maps, append aliasing, defensive copies) see `samber/cc-skills-golang@golang-safety` skill.
8- For channels and sync primitives see `samber/cc-skills-golang@golang-concurrency` skill.
9- For string/byte/rune choice see `samber/cc-skills-golang@golang-design-patterns` skill.
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11## Best Practices Summary
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131. **Preallocate slices and maps** with `make(T, 0, n)` / `make(map[K]V, n)` when size is known or estimable — avoids repeated growth copies and rehashing
142. **Arrays** SHOULD be preferred over slices only for fixed, compile-time-known sizes (hash digests, IPv4 addresses, matrix dimensions)
153. **NEVER rely on slice capacity growth timing** — the growth algorithm changed between Go versions and may change again; your code should not depend on when a new backing array is allocated
164. **Use `container/heap`** for priority queues, **`container/list`** only when frequent middle insertions are needed, **`container/ring`** for fixed-size circular buffers
175. **`strings.Builder`** MUST be preferred for building strings; **`bytes.Buffer`** MUST be preferred for bidirectional I/O (implements both `io.Reader` and `io.Writer`)
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