text: // +build OMIT
  
  package string_test
  
  import (
  	"fmt"
  	"strings"
  	"testing"
  )
  
  func TestIndex(t *testing.T) {
  	var tests = []struct {
  		s   string
  		sep string
  		out int
  	}{
  		{"", "", 0},
  		{"", "a", -1},
  		{"fo", "foo", -1},
  		{"foo", "foo", 0},
  		{"oofofoofooo", "f", 2},
  		// etc
  	}
  	for _, test := range tests {
  		actual := strings.Index(test.s, test.sep)
  		if actual != test.out {
  			t.Errorf("Index(%q,%q) = %v; want %v", test.s, test.sep, actual, test.out)
  		}
  	}
  }
  
  func BenchmarkIndex(b *testing.B) {
  	const s = "some_text=some☺value"
  	for i := 0; i < b.N; i++ {
  		strings.Index(s, "v")
  	}
  }
  
  func ExampleIndex() {
  	fmt.Println(strings.Index("chicken", "ken"))
  	fmt.Println(strings.Index("chicken", "dmr"))
  	// Output:
  	// 4
  	// -1
  }
  