Search Results

Search found 40745 results on 1630 pages for 'type deduction'.

Page 144/1630 | < Previous Page | 140 141 142 143 144 145 146 147 148 149 150 151  | Next Page >

  • Differentiate generic methods by type parameters only using reflection?

    - by Brian Vallelunga
    I'm trying to use reflection to get a specific MethodInfo of a class, but am unsure how to differentiate between the two following methods: public class Test { public IBar<T1> Foo<T1>(); public IBar<T1, T2> Foo<T1, T2>(); } How can I get a reference to the different Foo methods, assuming I know the number of type parameters? Just calling typeof(Test).GetMethod("Foo") will throw an exception that the method name is ambiguous and there aren't a differing number of parameters to check.

    Read the article

  • For what purpose does java have a float primitive type?

    - by Roman
    I heard plenty times different claims about float type in java. The most popular issues typicaly regard to converting float value to double and vice versa. I read (rather long time ago and not sure that it's actual now with new JVM) that float gives much worse performance then double. And it's also not recommended to use float in scientific applications which should have certain accuracy. I also remember that when I worked with AWT and Swing I had some problems with using float or double (like using Point2D.Float or Point2D.Double). So, I see only 2 advantages of float over double: it needs only 4 bytes while double needs 8 bytes JMM garantees that assignment operation is atomic with float variables while it's not atomic with double's. Are there any other cases where float is better then double? Do you use float's in your applications? It seems to me that the only valuable reason java has float is backward compatibility.

    Read the article

  • which lightweight SQL Server type could I use on my Dev machine for a C# VS2010 project?

    - by Greg
    Hi, Which lightweight SQL Server type could I use on my Dev machine for a C# VS2010 project? (e.g. sql server express, sql server ce, full version etc). That is, I'm running on a VMWare fusion instance on my MacBook, and just want something to develop against for a C# VS2010 project. I'm planning on having a simple database (not many tables) but will use Entity Framework. I haven't used SQL Server before so a quick pointer re what is the best database admin interface/app to use for the version you recommend (e.g. to create database, tables etc).

    Read the article

  • Cannot implicitly convert type ... to ... problem

    - by Younes
    I have this code: public static IEnumerable<dcCustomer> searchCustomer(string Companyname) { TestdbDataContext db = new TestdbDataContext(); IEnumerable<dcCustomer> myCustomerList = (from Customer res in db.Customers where res.CompanyName == Companyname select res); return myCustomerList; } And whatever i try i keep getting the convert error. Error 1 Cannot implicitly convert type 'System.Collections.Generic.IEnumerable<ConnectionWeb.Customer>' to 'System.Collections.Generic.IEnumerable<ConnectionWeb.DAL.dcCustomer>'. An explicit conversion exists (are you missing a cast?) \\srv01\home$\Z****\Visual Studio 2008\Projects\ConnectionWeb\ConnectionWeb\DAL\dcCustomer.cs 63 20 ConnectionWeb I want to try get myCustomerList to keep the values in an enumerator and return it.

    Read the article

  • What tricks can be used to type and edit code faster?

    - by Thomas
    As Jeff Atwood noted, we are typists first, programmers second. Fast typing and editing may not be essential to be a good programmer, but it certainly helps. I noticed that I consciously and subconsciously use various tricks to get my intent across to the computer as fast as possible. What tricks can be used to type and edit code faster? I'm hoping to collect a nice list here that we can all learn from, so that we can be ever so slightly more productive. One trick per answer please! (This is not about typing speed in general. There are other questions about that. It's also not about general answers like "learn your editor's shortcut keys". Think of this topic as micro-optimizations for specific cases. See my own answers for examples of what I mean.)

    Read the article

  • Styling the selection color of an input type=text, possible?

    - by Tommy
    Having an input <input type="text" id="myTest" value="bla bla bla"/> and doing this (using jQuery) $('#myTest').select(); causes "bla bla bla" to be selected with default dark blue selection color. Now, is there any way I can change this color using css? css3 can change selection using for instance ::-moz-selection { background: #ffb7b7; } but this only works on text in other elements, not in html inputs. Any ideas? /T

    Read the article

  • How to process <input type="file" name="test1[f]" /> in PHP?

    - by user198729
    var_dump($_FILES) gives the following: array 'test1' => array 'name' => array 'f' => string 'ntuser.dat.LOG' (length=14) 'type' => array 'f' => string 'application/octet-stream' (length=24) 'tmp_name' => array 'f' => string 'D:\wamp\tmp\php223.tmp' (length=22) 'error' => array 'f' => int 0 'size' => array 'f' => int 0 Why is http designed this way?How can I get the file by $_FILES['test1']['f']?

    Read the article

  • Sql: simultaneous aggregate from two tables

    - by Ash
    I have two tables: a Files table, which includes the file type, and a File Properties table, which references the file table via a foreign key. Sample Files table: | id | name | type | --------------------- | 1 | file1 | zip | | 2 | file2 | zip | | 3 | file3 | zip | | 4 | file4 | jpg | And the Properties table: | file_id | property | ----------------------- | 1 | x | | 2 | x | I want to make a query, which shows the count of each file type, and how many files of that type have a property. So in the example, the result would be | type | filecount | prop count | ---------------------------------- | zip | 3 | 2 | | jpg | 1 | 0 | I could accomplish this by select f.type, (select count(id) from files where type = f.type), count(fp.id) from files as f, file_properties as fp where f.id = fp.file_id group by f.type; But this seems very suboptimal and is very slow. Any better way to do this?

    Read the article

  • Is there a module that implements an efficient array type in Erlang?

    - by dsmith
    I have been looking for an array type with the following characteristics in Erlang. append(vector(), term()) O(1) nth(Idx, vector()) O(1) set(Idx, vector(), term()) O(1) insert(Idx, vector(), term()) O(N) remove(Idx, vector()) O(N) I normally use a tuple for this purpose, but the performance characteristics are not what I would want for large N. My testing shows the following performance characteristics... erlang:append_element/2 O(N). erlang:setelement/3 O(N). I have started on a module based on the clojure.lang.PersistentVector implementation, but if it's already been done I won't reinvent the wheel.

    Read the article

  • Programatically find out a file type by looking its binary content. Possible?

    - by daemonkid
    I have a c# component that will recieve a file of the following types .doc, .pdf, .xls, .rtf These will be sent by the calling siebel legacy app as a filestream. So... [LegacyApp] {Binary file stream} [Component] The legacy app is a black box that cant be modified to tell the component what file type (doc,pdf,xls) it is sending. The component needs to read this binary stream and create a file on the filesystem with the right extension. Any ideas? Thanks for your time.

    Read the article

  • How do I use Declarations (type, inline, optimize) in Scheme?

    - by kunjaan
    How do I declare the types of the parameters in order to circumvent type checking? How do I optimize the speed to tell the compiler to run the function as fast as possible like (optimize speed (safety 0))? How do I make an inline function in Scheme? How do I use an unboxed representation of a data object? And finally are any of these important or necessary? Can I depend on my compiler to make these optimizations? thanks, kunjaan.

    Read the article

  • What is wrong with this simple type definition? (Expecting one more argument to...)

    - by fluteflute
    basic.hs: areaCircle :: Floating -> Floating areaCircle r = pi * r * r Command: *Main> :l basic.hs [1 of 1] Compiling Main ( Sheet1.hs, interpreted ) Sheet1.hs:2:15: Expecting one more argument to `Floating' In the type signature for `areaCircle': areaCircle :: Floating -> Floating Failed, modules loaded: none. I see that areaCircle :: Floating a => a -> a loads as expected. Why is the above version not acceptable?

    Read the article

  • What's wrong with addlistener... how do i fire my event

    - by KoolKabin
    I am using the following functions to do my task. It works fine when cursor moves away from textbox but if i want to fire the same event from code say like next function i get error... function addEvent( obj, type, fn ) { if (obj.addEventListener) { obj.addEventListener( type, fn, false ); } else if (obj.attachEvent) { obj["e"+type+fn] = fn; obj[type+fn] = function() { obj"e"+type+fn; } obj.attachEvent( "on"+type, obj[type+fn] ); } else { obj["on"+type] = obj["e"+type+fn]; } } function addEventByName(ObjName, event, func){ MyEle = document.getElementsByName(ObjName); addEvent(MyEle[0], event, func); } addEventByName("txtBox", 'blur', function(){ alert('hello'); }); function fire(){ x = document.getElementsByName('txtBox')[0]; x.blur(); //gives error x.onblur(); //gives error }

    Read the article

  • Is it possible to specify a return type of "Derivative(of T)" for a MustOverride sub in VB.NET?

    - by Casey
    VB.NET 2008 .NET 3.5 I have two base classes that are MustInherit (partial). Let's call one class OrderBase and the other OrderItemBase. A specific type of order and order item would inherit from these classes. Let's call these WebOrder (inherits from OrderBase) and WebOrderItem (inherits from OrderItemBase). Now, in the grand scheme of things WebOrder is a composite class containing a WebOrderItem, like so: Public Class WebOrder Inherits OrderBase Public Property OrderItem() as WebOrderItem End Property End Class Public Class WebOrderItem Inherits OrderItemBase End Class In order to make sure any class that derives from OrderBase has the OrderItem property, I would like to do something like this in the OrderBase class: Public MustInherit Class OrderBase Public MustOverride Property OrderItem() as Derivative(Of OrderItemBase) End Class In other words, I want the derived class to be forced to contain a property that returns a derivative of OrderItemBase. Is this possible, or should I be using an entirely different approach?

    Read the article

  • How can the generic method called know the type of the generic return?

    - by Paulo Guedes
    I couldn't find a duplicate for this question for Java, although there are a lot of them for C#. I have this method: public <T> T getSomething() { // } According to the type of T, I will have a different return. For example: String a = getSomething(); int b = getSomething(); For a, my method will return a specific String. For b, it will return a specific int. And so on. It seems that this can be done with typeof() in C#. How can I achieve it in Java?

    Read the article

  • Which type of Rails model association should I use in this situation?

    - by jstayton
    I have two models/tables in my Rails application: discussions and comments. Each discussion has_many comments, and each comment belongs_to a discussion. My discussions table also includes a first_comment_id column and last_comment_id column for convenience and speed. I want to be able to call discussion.last_comment for the last comment model, but the following (in my discussion model) isn't working to make this happen: has_one :first_comment, :class_name => "Comment" has_one :last_comment, :class_name => "Comment" When I call discussion.last_comment, the following SQL is run: SELECT * FROM `comments` WHERE (`comments`.discussion_id = 1) LIMIT 1 It's using the discussions.id column to join against comments.discussion_id, when I want it to join discussions.last_comment_id against comments.id. Am I using the wrong type of association here? Thanks for your help!

    Read the article

  • Problem with number/type of arguments passed to an overloaded c++ constructor wrapped with swig.

    - by MiKo
    I am trying to wrap a c++ class (let's call it "Spam") written by someone else with swig to expose it to Python. After solving several problems, I am able to import the module in python, but when I try to create an object of such class I obtain the following error: foo = Spam.Spam('abc',3) Traceback (most recent call last): File "<stdin>", line 1, in <module> File "Spam.py", line 96, in __init__ this = _Spam.new_Spam(*args) NotImplementedError: Wrong number of arguments for overloaded function 'new_Spam'. Possible C/C++ prototypes are: Spam(unsigned char *,unsigned long,bool,unsigned int,SSTree::io_action,char const *) Spam(unsigned char *,unsigned long,bool,unsigned int,SSTree::io_action) Spam(unsigned char *,unsigned long,bool,unsigned int) Spam(unsigned char *,unsigned long,bool) Spam(unsigned char *,unsigned long) Googling around, I realized that the error is probably caused by the type of the arguments and not by the number (which is quite confusing), but I still cannot identify. I suspect the problem lies in passing a string as the first argument, but have no idea on how to fix it (keep in mind that I know almost no c/c++).

    Read the article

  • C# Reflection - How can I tell if object o is of type KeyValuePair and then cast it?

    - by Logan
    Hi All I'm currently trying to write a Dump() method from LinqPad equivalent iin C# for my own amusment. I'm moving from Java to C# and this is an exercise rather than a business requirement. I've got almost everything working except for Dumping a Dictionary. The problem is that KeyValuePair is a Value type. For most other Value types I simply call the ToString method but this is insufficient as the KeyValuePair may contain Enumerables and other objects with undesirable ToString methods. So I need to work out if it's a KeyValuePair and then cast it. In Java I could use wildcard generics for this but I don't know the equivalent in C#. Your quest, given an object o, determine if it's a KeyValuePair and call Print on its key and value. Print(object o) { ... } Thanks!

    Read the article

  • Why Is It That Generics Constraint Can't Be Casted to Its Derived Type?

    - by Ngu Soon Hui
    It is quite puzzling to find out that Generics Constraint Can't Be Casted to Its Derived Type. Let's say I have the following code: public abstract class BaseClass { public int Version { get { return 1; } } public string FixString { get; set; } public BaseClass() { FixString = "hello"; } public virtual int GetBaseVersion() { return Version; } } public class DeriveClass: BaseClass { public new int Version { get { return 2; } } } And guess what, this method will return a compilation error: public void FreeConversion<T>(T baseClass) { var derivedMe = (DeriveClass)baseClass; } I would have to cast the baseClass to object first before I can cast it to DerivedClass. Seems to me pretty ugly. Why this is so?

    Read the article

  • How to look up an NHibernate entity's table mapping from the type of the entity?

    - by snicker
    Once I've mapped my domain in NHibernate, how can I reverse lookup those mappings somewhere else in my code? Example: The entity Pony is mapped to a table named "AAZF1203" for some reason. (Stupid legacy database table names!) I want to find out that table name from the NH mappings using only the typeof(Pony) because I have to write a query elsewhere. How can I make the following test pass? private const string LegacyPonyTableName = "AAZF1203"; [Test] public void MakeSureThatThePonyEntityIsMappedToCorrectTable() { string ponyTable = GetNHibernateTableMappingFor(typeof(Pony)); Assert.AreEqual(LegacyPonyTableName, ponyTable); } In other words, what does the GetNHibernateTableMappingFor(Type t) need to look like?

    Read the article

  • What is the pythonic way to add type information to an object's attributes?

    - by Tikitu
    I'm building classes where I know the types of the attributes, but Python of course doesn't. While it's un-pythonic to want to tell it, supposing I do want to, is there an idiomatic way to do so? Why: I'm reading in serialised data (without type information) involving objects-nested-inside-objects. It's easy to put it into nested dictionaries, but I want it in objects of my class-types, to get the right behaviours as well as the data. For instance: suppose my class Book has an attribute isbn which I will fill with an ISBNumber object. My serialised data gives me the isbn as a string; I would like to be able to look at Book and say "That field should be filled by ISBNumber(theString)." Bonus glee for me if the solution can be applied to classes I get from someone else without editing their code.

    Read the article

  • Using SSIS, how do you read a datetime field into a variable that is of Data Type string?

    - by Mark Kadlec
    This one has bugged me for the longest time and a great question to ask the Stackoverflow users I think. I have a rather large SSIS flow that uses a string variable to store the datetime. I would now like to dynamically read the datetime value from the database, but how would you construct the SSIS to do this? My first obvious thought would be to simply execute a SQL task to get the datetime and store it in the variable, but got the "differs from the current variable type" error. Is there a simple way to convert the database datetime into a String variable? Any help from the community would be appreciated,

    Read the article

  • is right to implement a business logic in the type binding DI framwork?

    - by Martino
    public IRedirect FactoryStrategyRedirect() { if (_PasswordExpired) { return _UpdatePasswordRedirectorFactory.Create(); } else { return _DefaultRedirectorFactory.Create(); } } This strategy factory method can be replaced with type binding and when clause: Bind<IRedirect>.To<UpdatePasswordRedirector>.When(c=> c.kernel.get<SomeContext>().PasswordExpired()) Bind<IRedirect>.To<DefaultRedirector>.When(c=> not c.kernel.get<SomeContext>().PasswordExpired()) I wonder which of the two approaches is the more correct. What are the pros and cons. Especially in the case in which the logic is more complex with more variables to test and more concrete classes to return. is right to implement a business logic in the binding?

    Read the article

  • Open generic interface types of open implementation don't equal interface type?

    - by George Mauer
    Here's a test that should, in my opinion be passing but is not. [TestMethod] public void can_get_open_generic_interface_off_of_implementor() { typeof(OpenGenericWithOpenService<>).GetInterfaces().First() .ShouldEqual(typeof(IGenericService<>)); } public interface IGenericService<T> { } public class OpenGenericWithOpenService<T> : IGenericService<T> { } Why does this not pass? Given Type t = typeof(OpenGenericWithOpenService<>) how do I get typeof(IGenericService<)? I'm generally curious, but if you're wondering what I'm doing, I'm writing a Structuremap convention that forwards all interfaces implemented by a class to the implementation (as a singleton).

    Read the article

  • In a C++ template, is it allowed to return an object with spesific type parameters?

    - by nieldw
    When I've got a template with certain type parameters, is it allowed for a function to return an object of this same template, but with different types? In other words, is the following allowed? template<class edgeDecor, class vertexDecor, bool dir> Graph<edgeDecor,int,dir> Graph<edgeDecor,vertexDecor,dir>::Dijkstra(vertex s, bool print = false) const { /* Construct new Graph with apropriate decorators */ Graph<edgeDecor,int,dir> span = new Graph<edgeDecor,int,dir>(); /* ... */ return span; }; If this is not allowed, how can I accomplish the same kind of thing?

    Read the article

< Previous Page | 140 141 142 143 144 145 146 147 148 149 150 151  | Next Page >