Add a generic BindFor that can usually replace BindTo

Author: jwreschnig-utiq

options.go

@@ -248,6 +248,13 @@ func BindTo(impl, iface any) Option {
 	})
 }
 
+// BindFor allows binding of implementations to the compile-time type. It
+// is equivalent to BindTo(v, (*T)(nil)), but can usually infer the
+// correct type T.
+func BindFor[T any](v T) Option {
+	return BindTo(v, (*T)(nil))
+}
+
 // BindToProvider binds an injected value to a provider function.
 //
 // The provider function must have one of the following signatures:

options_test.go

@@ -43,6 +43,26 @@ func TestBindTo(t *testing.T) {
 	assert.Equal(t, "foo", saw)
 }
 
+func TestBindFor(t *testing.T) {
+	type iface interface {
+		Method()
+	}
+
+	saw := ""
+	method := func(i iface) error {
+		saw = string(i.(impl)) //nolint
+		return nil
+	}
+
+	var cli struct{}
+
+	p, err := New(&cli, BindFor(iface(impl("foo"))))
+	assert.NoError(t, err)
+	err = callFunction(reflect.ValueOf(method), p.bindings)
+	assert.NoError(t, err)
+	assert.Equal(t, "foo", saw)
+}
+
 func TestInvalidCallback(t *testing.T) {
 	type iface interface {
 		Method()