package main import ( "errors" "fmt" "reflect" "github.com/expr-lang/expr" ) type Number interface { int | uint | uint32 | int32 | uint64 | int64 | float32 | float64 } func TryStrToNum[T Number](str string) (retValue T, err error) { program, err := expr.Compile(str, expr.AsKind(reflect.TypeOf(retValue).Kind())) if err != nil { fmt.Printf("Compile Error: %s, %v\n", str, err) return	} v, err := expr.Run(program, nil) if err != nil { fmt.Printf("Run Error: %s, %v\n", str, err) return	} retValue, flag := v.(T) if !flag { fmt.Printf("StrToNumber Error: %s, %v", str, v) return retValue, errors.New(fmt.Sprintf("TryStrToNum error: %s", str))	} return retValue, nil } func main() { fmt.Println(TryStrToNum[int32]("1")) } /* Compile Error: 1, expected int32, but got int 0 expected int32, but got int */