try/try.go

@@ -47,14 +47,7 @@ type call struct {
 }
 
 // FromErr wraps a standard error into a try-compatible one with extended stack info.
-func FromErr(err error) Err {
+func FromErr(err error) *tryErr {
-	// If the error is already try-compatible, return
-	//nolint:errorlint
-	cterr, ok := err.(Err)
-	if ok {
-		return cterr
-	}
-
 	terr := &tryErr{err: err, callStack: []call{}}
 
 	pc, _, _, ok := runtime.Caller(0)
@@ -89,7 +82,7 @@ func FromErr(err error) Err {
 }
 
 // NewErr creates a new try-compatible error with extended stack info.
-func NewErr(msg string) Err {
+func NewErr(msg string) *tryErr {
 	return FromErr(errors.New(msg))
 }
 

try/try_test.go

@@ -220,22 +220,6 @@ func TestReturnStd(t *testing.T) {
 	}
 }
 
-func TestCheckTryErr(t *testing.T) {
-	testErr := NewErr("TestErr")
-
-	tf := func() (err Err) {
-		defer Return(&err)
-		Check(testErr)
-		return
-	}
-
-	err := tf()
-
-	if err != testErr {
-		t.Fail()
-	}
-}
-
 func ExampleReturn() {
 	var err Err
 	defer Return(&err)