java - How is generic information used by the compiler if generic static methods are called? -

-

I have a question about the general type. I have written my own Iterator type and if I repeat it again If nothing is there, then want to return empty repeaters.

The following code works, 

  @Override public iterator & lt; MyType & gt; Iterator () (last Iterator & lt; methype & gt; IARAR = collection. Return calculation & gt; New MiITATOR (): ITER;}

However, it does not work , If written in a row like this: 

  @ override public iterator  iterator () {return calculation> New MyITter (): collection exempt ();}

I get an error and type to solve it: 

  @ override public Iterator & lt; MyType & Gt; iterator () {w} (Iterator & lt; MyType & gt;) (Count> New Miterator: Collection Executioner ());}

This artist goes to an arbitrary warning, first There is no warning in the example.

When I move the artist from inside, it does not work either: 

  @override public iterator & lt; MyType & gt; Iterator () {Return calculation> New Age Iterator (): (Iterator & Lt; MyType & gt;) Collection. And ();}

My question is: why the compiler can not determine that follows right after the examples, but the first. Why does the 3rd edition work, but not in the last one? Variants are basically similar in my impressions.

If you want to work it out, use it syntax: 

  Return Collection.  emptyIterator ();

This is the way to give a stable method to normalize.

If you want to call then. Iterator & lt; Object & gt; which is incompatible with your return type.

You can not even be cast because Iterator & lt; MyType & gt; Does not expand iterator & lt; Object & gt; .


Comments

Post a Comment

Popular posts from this blog

import - Python ImportError: No module named wmi -

-
I followed the instructions for downloading WMI for Python When I try to run the code for C.Win32_Service (StartMode = "Auto", state = "Stopped") import wmi c = wmi.WMI (): if Raw_input ("restart% s?"% S.Caption) .upper () == "Y": s.StartService () I got the error < Code> traceback (most recent call end): file ". \", Line 1, edit: I am using Python 2.7.6 EDIT2: I am running 64-bit Windows 2008 R2, and I've downloaded WMI-1.4.9.zip (md5). I removed the content and put it in D: Python \ Tools \ Scripts I executed dragon setup.py.install I said D : \ Python \ tools \ scripts to% PATH% and when I execute the code for C.Win32_Service (StartMode = "Auto", state = "Stopped") import wmi c = Wmi.WMI (): If raw_input ("Restart% s?"% S. Caption). () == "Y": s.StartService () error me Gets traceback (most recent call final): File ". See \", line 1, &
Read more

Editing Python Class in Shell and SQLAlchemy -

-
I am working on the terminal on a shell script after this tutorial SQLAlchemy tutorial. I need to type gt; & Gt; & Gt; Sqlalchemy import column, integer, string & gt; & Gt; & Gt; Class user (base): __tablename__ = 'users' id = column (integer, primary_key = true) name = column (string) absolute name = column (string) password = column (string) def __repr __ (self): return "& lt ; User (name = '% s', absolute name = '% s', password = '% s') & gt; "% (Self.name, self.fullname, self.password) After the problem I have typed the password = column (string) I hit twice and changed .... >> I then took everything back but then an error was thrown because the class already exists ... I am not completely sure how to fix it. How do I open that slip in the shell script and edit it (Add DF to DRR) The error thrown below: / user / giripeters / TFSQLLX / Lib / python2.7 / site-packages / sqlalchemy / ext / decla
Read more

c# - MySQL Parameterized Select Query joining tables issue -

-
I am using parameterized select questions in conjunction with my program and it works entirely, When I try to join the table Everything I have done is a small fraction: using (MySqlCommand cmd = new MySqlCommand (paramQuery) ToSql (), Connection)) /etc/ paramQuery.ToSql () Equal: "Select TableOne ID, Tableon, Department, Tablet. One by name table, Table 2 h Yes TableOnEID = @Pharmak "* / for (Int Index = 0; Index and Lt; ParamariX Parameter (.c calculation; Index ++) Cmd.Parameters.AddWithValue (paramQuery.Parameters (). ElementAt (index). , ParamQuery.Parameters (). ElementAt (index) .Value); / * ParamQuery.Parameters (). ElementAt (index) .k = "@most 0" paramQuery.Parameters (). ElementAt (index) .Value = "tableTwo.ID" * / MySqlDataReader Reader = cmd.ExecuteReader (); While (reader.Read ()) {// do stuff} } One of the tables I attempt to join is For the table, two with the same id for all. Is there something that I'm doing wrong?
Read more