Update docs, compare to normal not-equals null check

LICENSE

@@ -0,0 +1,18 @@
+Copyright 2020 Gregory Eremin
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

README.md

@@ -1,8 +1,35 @@
-## Checking for `nil` in Go
+# isnil
+
+`nil` check that works for interfaces too. Example code and benchmarks.
 
 Benchmarks:
 ```
-BenchmarkIsNilBasic-8           200000000            9.47 ns/op
-BenchmarkIsNilInterface-8       200000000            9.18 ns/op
-BenchmarkIsNilNil-8             1000000000           2.03 ns/op
+#
+# x != nil
+#
+
+# nil pointer
+BenchmarkEqNilBasic
+BenchmarkEqNilBasic-8           1000000000           0.247 ns/op
+
+# nil interface
+BenchmarkEqNilInterface
+BenchmarkEqNilInterface-8       1000000000           0.247 ns/op
+
+
+#
+# IsNil(x)
+#
+
+# nil pointer
+BenchmarkIsNilBasic
+BenchmarkIsNilBasic-8           274689241            4.37 ns/op
+
+# (*struct{})(nil)
+BenchmarkIsNilInterface
+BenchmarkIsNilInterface-8       277561260            4.26 ns/op
+
+# nil
+BenchmarkIsNilNil
+BenchmarkIsNilNil-8             803470719            1.48 ns/op
 ```

isnil_test.go

@@ -31,6 +31,21 @@ func TestIsNil(t *testing.T) {
 	}
 }
 
+func BenchmarkEqNilBasic(b *testing.B) {
+	var v *int
+	for i := 0; i < b.N; i++ {
+		_ = (v != nil)
+	}
+}
+
+func BenchmarkEqNilInterface(b *testing.B) {
+	var v interface{}
+	v = (*foo)(nil)
+	for i := 0; i < b.N; i++ {
+		_ = (v != nil)
+	}
+}
+
 func BenchmarkIsNilBasic(b *testing.B) {
 	var v *int
 	for i := 0; i < b.N; i++ {