Fix for 1.18-rc1

Author: BooleanCat

.github/workflows/test.yaml

@@ -14,5 +14,5 @@ jobs:
       - uses: actions/setup-go@v2
         with:
           stable: "false"
-          go-version: "1.18.0-beta2"
+          go-version: "1.18.0-rc1"
       - run: go test -v ./...

README.md

@@ -2,7 +2,7 @@
 
 A general purpose library offering functional helpers for Golang.
 
-_*Note: this library requires Go 1.18, which is currently in beta.*_
+_*Note: this library requires Go 1.18, which is currently a release candidate.*_
 
 ```go
 // Find the first 5 prime numbers

constraints/constraints.go

@@ -0,0 +1,21 @@
+package constraints
+
+type Signed interface {
+	~int | ~int8 | ~int16 | ~int32 | ~int64
+}
+
+type Unsigned interface {
+	~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr
+}
+
+type Integer interface {
+	Signed | Unsigned
+}
+
+type Float interface {
+	~float32 | ~float64
+}
+
+type Ordered interface {
+	Integer | Float | ~string
+}

internal/assert/assert.go

@@ -29,7 +29,9 @@ func False(t *testing.T, b bool) {
 func Nil(t *testing.T, v interface{}) {
 	t.Helper()
 
-	Equal(t, v, nil)
+	if v != nil {
+		t.Errorf("expected `%v` to equal `nil`", v)
+	}
 }
 
 func NotNil(t *testing.T, v interface{}) {

iter/filters/filters.go

@@ -1,6 +1,6 @@
 package filters
 
-import "constraints"
+import "github.com/BooleanCat/go-functional/constraints"
 
 // IsZero is a filter intended for use with iter.Filter that returns true when
 // the provided value is equal to its zero value.

iter/ops/ops.go

@@ -1,8 +1,7 @@
 package ops
 
 import (
-	"constraints"
-
+	"github.com/BooleanCat/go-functional/constraints"
 	"github.com/BooleanCat/go-functional/option"
 	"github.com/BooleanCat/go-functional/result"
 )