append_test.go

package append

import "testing"

var result []T

const size = 10000

type T int

func BenchmarkCopy(b *testing.B) {
    orig := make([]T, size)

    for n := 0; n < b.N; n++ {
        cpy := make([]T, len(orig))
        copy(cpy, orig)
        orig = cpy
    }
    result = orig
}

func BenchmarkAppend(b *testing.B) {
    orig := make([]T, size)

    for n := 0; n < b.N; n++ {
        cpy := append([]T{}, orig...)
        orig = cpy
    }
    result = orig
}

func BenchmarkAppendPreCapped(b *testing.B) {
    orig := make([]T, size)

    for n := 0; n < b.N; n++ {
        cpy := append(make([]T, 0, len(orig)), orig...)
        orig = cpy
    }
    result = orig
}