Search Results

Search found 5377 results on 216 pages for 'explicit cast operator'.

Page 154/216 | < Previous Page | 150 151 152 153 154 155 156 157 158 159 160 161  | Next Page >

• So I dynamically load a jar at runtime how do I use it?

  - by justinhj

  So question 194698 shows how to load a jar file at runtime and you can load individual named classes and get a Class object. Now my problem is I want to be able to cast those Classes to the types they really are, but I can't because I can't use an import since the whole point is to load it at runtime rather than compile time. It seems like the way to go is to use reflection to discover the functions and field names, but that seems brittle since the API in the jar files could change and the code won't break until it is run. Is there a better way?

  Read the article

• C pointer initialization and dereferencing, what's wrong here?

  - by randombits

  This should be super simple, but I'm not sure why the compiler is complaining here. #include <stdio.h> #include <stdlib.h> int main(int argc, char *argv[]) { int *n = 5; printf ("n: %d", *n); exit(0); } Getting the following complaints: foo.c: In function ‘main’: foo.c:6: warning: initialization makes pointer from integer without a cast I just want to print the value that the pointer n references. I'm dereferencing it in the printf() statement and I get a segmentation fault. Compiling this with gcc -o foo foo.c.

  Read the article

• Hex to bin after logical operations

  - by user355926

  I want: 111 || 100 ---> 111, not 1 100 && 100 ---> 100, not 1 101 && 010 ---> 000, not 0 Broken code #include <stdio.h> main(void){ string hexa = 0xff; strig hexa2 = 0xf1; // CONVERT TO INT??? cast int hexa3 = hexa || hexa2; int hexa4 = hexa && hexa2; puts(hexa3); puts(hexa4); }

  Read the article

• converting tag number to int

  - by Ehtesham Sajed

  i m using Visual C++2008. i've assigned tag value=2 of all buttons from button property(using drag n drop). now i want to make some math calculation with tag value. need to change it in int. what is the default data type tag? i used this code, //code sample if(((int)this-button1-Tag)((int)this-button2-Tag)((int)this-button3-Tag)==50) { ........ //i.e, if tag value of button1*tag value of button2*tag value of button 3==50 then... ........ } generated following run time error on a messegebox An unhandled exception of type 'System.InvalidCastException' occurred in learncpp1.exe Additional information: Specified cast is not valid.

  Read the article

• What is the best solution to replace a new memory allocator in an existing code?

  - by O. Askari

  During the last few days I've gained some information about memory allocators other than the standard malloc(). There are some implementations that seem to be much better than malloc() for applications with many threads. For example it seems that tcmalloc and ptmalloc have better performance. I have a C++ application that uses both malloc and new operators in many places. I thought replacing them with something like ptmalloc may improve its performance. But I wonder how does the new operator act when used in C++ application that runs on Linux? Does it use the standard behavior of malloc or something else? What is the best way to replace the new memory allocator with the old one in the code? Is there any way to override the behavior or new and malloc or do I need to replace all the calls to them one by one?

  Read the article

• How do I use a custom select statement in Hibernate using the HibernateDaoSupport class

  - by Bill Leeper

  I am trying to write a custom select statement in Hibernate using the getHibernateTemplate() method. I am having problems with the resulting mapping. Example Code: List<User> users = getHibernateTemplate().find("Select user, sysdate as latestPost from User as user"); for (User user : users) { assertNotNull(users.name); } The goal of the above line is to eventually have a join where I get the max(date) of posts made by the user. The problem I am having is that the resulting users list is not a list of User objects and I get a class cast exception. Hopefully that is enough code. It is a greatly simplified version of my problem and a combination of snippets from various parts of my application.

  Read the article

• are Hierarchical SIngletons in Java possible?

  - by Zach H

  I've been toying with an interesting idea (No idea if I'll include it in any code, but it's fun to think about) Let's say we have a program that requires a large number of classes, all of a certain subclass. And those classes all need to be singletons. Now, we could write the singleton pattern for each of those classes, but it seems wasteful to write the same code over and over, and we already have a common base class. It would be really nice to create a getSingleton method of A that when called from a subclass, returns a singleton of the B class (cast to class A for simplicity) class A{ public A getSingleton(){ //Wizardry } } class B extends A{ } A blargh = B.getSingleton() A gish = B.getSingleton() if(A == B) System.out.println("It works!") It seems to me that the way to do this would be to recognize and call B's default constructor (assuming we don't need to pass anything in.) I know a little of the black magic of reflection in Java, but i'm not sure if this can be done. Anyone interested in puzzling over this?

  Read the article

• C++ / Java: Toggle boolean statement?

  - by Martijn Courteaux

  Hi, Is there a short way to toggle a boolean? With integers we can do operations like this: int i = 4; i *= 4; // equals 16 /* Which is equivalent to */ i = i * 4; So is there also something for booleans (like the *= operator for ints)? In C++: bool booleanWithAVeryLongName = true; booleanWithAVeryLongName = !booleanWithAVeryLongName; // Can it shorter? booleanWithAVeryLongName !=; // Or something? In Java: boolean booleanWithAVeryLongName = true; booleanWithAVeryLongName = !booleanWithAVeryLongName; // Can it shorter? booleanWithAVeryLongName !=; // Or something?

  Read the article

• How can I pass a type as a parameter in scala?

  - by rsan

  I'm having a really hard time trying to figure out how can I store or pass a type in scala. What I want to achive is something like this: abstract class Foo( val theType : type ) object Foo{ case object Foo1 extends Foo(String) case object Foo2 extends Foo(Long) } So at some point I can do this: theFoo match{ case String => "Is a string" case Long => "Is a long" } and when obtaining the object being able to cast it: theFoo.asInstanceOf[Foo1.theType] Is this possible? If is possible, is a good aproach? What I'm trying to achieve ultimately is writing a pseudo schema for byte stream treatment. E.g if I have an schema Array(Foo1,Foo1,Foo2,Foo3,Foo1) I could parse Arrays of bytes that complain with that schema, if at some point I have a different stream of bytes I could just write a new schema Array(Foo3, Foo4, Foo5) without having to reimplement parsing logic. Regards,

  Read the article

• java.lang.classcastExcption

  - by Tara Singh

  Hi, I have an array list of objects in my application. private static ArrayList<Player> userList=new ArrayList<Player>(); In my application, I am converting this list to byte array and then sending it to other clients. At client When I am trying to cast it back to the ArrayList, its giving me casting error. I am doing this in client side after receiving this list as byte array: ArrayList<Player> pl = (ArrayList<Player>) toObject(receivedByteArray); where toObject is my function to convert the byte array to object; Any Suggestions please !!! Thanks.

  Read the article

• ActionScript: Using 'in' on protected/private variables?

  - by David Wolever

  Is there any way to mimic the in operator, but testing for the existence of protected or private fields? For example, this: <mx:Script><![CDATA[ public var pub:Boolean = true; protected var prot:Boolean = true; private var priv:Boolean = true; ]]></mx:Script> <mx:creationComplete><![CDATA[ for each (var prop in ["pub", "prot", "priv", "bad"]) trace(prop + ":", prop in this); ]]></mx:creationComplete> Will trace: pub: true prot: false priv: false bad: false When I want to see: pub: true prot: true priv: true bad: false

  Read the article

• How to print size_t variable portably?

  - by ArunSaha

  I have a variable of type size_t, and I want to print it using printf(). What format specifier do I use to print it portably? In 32-bit machine, %u seems right. I compiled with g++ -g -W -Wall -Werror -ansi -pedantic, and there was no warning. But when I compile that code in 64-bit machine, it produces warning. size_t x = <something>; printf( "size = %u\n", x ); warning: format '%u' expects type 'unsigned int', but argument 2 has type 'long unsigned int' The warning goes away, as expected, if I change that to %lu. The question is, how can I write the code, so that it compiles warning free on both 32- and 64- bit machines? Edit: I guess one answer might be to "cast" the variable into an unsigned long, and print using %lu. That would work in both cases. I am looking if there is any other idea. (C, C++)

  Read the article

• Is call to function object inlined?

  - by dehmann

  In the following code, Foo::add calls a function via a function object: struct Plus { inline int operator()(int x, int y) const { return x + y; } }; template<class Fct> struct Foo { Fct fct; Foo(Fct f) : fct(f) {} inline int add(int x, int y) { return fct(x,y); // same efficiency adding directly? } }; Is this the same efficiency as calling x+y directly in Foo::add? In other words, does the compiler typically directly replace fct(x,y) with the actual call, inlining the code, when compiling with optimizations enabled?

  Read the article

• Unboxing object containing a value which is known to be assignable to an integer variable

  - by Wim Coenen

  If I have an object instance and I know it is actually a boxed integer, then I can simply cast it back to int like this: object o = GetSomethingByName("foo"); int i = (int)o; However, I don't actually know that the value is an integer. I only know that it can be assigned to an integer. For example, it could be a byte, and the above code would throw InvalidCastException in that case. Instead I would have to do this: object o = GetSomethingByName("foo"); int i = (int)(byte)o; The value could also be a short, or something else which can be assigned to an int. How do I generalize my code to handle all those cases (without handling each possibility separately)?

  Read the article

• Best way to validate currency input?

  - by Abe Miessler

  I have created the TextBox and CompareValidator below which I thought would allow input in the following forms: 5 5.00 $5.00 Unfortunately it's not allowing the version with the dollar sign in it. What is the point of doing a type check against currency if you don't allow the dollar sign? Is there a way to allow this symbol? <asp:TextBox ID="tb_CostShare" runat="server" Text='<%# Eval("CostShare", "{0:$0.00}")%>' CausesValidation="true" /> <asp:CompareValidator ID="vld_CostShare" runat="server" ControlToValidate="tb_CostShare" Operator="DataTypeCheck" Type="Currency" ValidationGroup="vld" ErrorMessage="You must enter a dollar amount for 'Cost Share'." />

  Read the article

• How to retrieve all keys (or values) from a std::map?

  - by Owen

  This is one of the possible ways I come out: struct RetrieveKey { template <typename T> typename T::first_type operator()(T keyValuePair) const { return keyValuePair.first; } }; map<int, int> m; vector<int> keys; // Retrieve all keys transform(m.begin(), m.end(), back_inserter(keys), RetrieveKey()); // Dump all keys copy(keys.begin(), keys.end(), ostream_iterator<int>(cout, "\n")); Of course, we can also retrieve all values from the map by defining another functor RetrieveValues. Is there any other way to achieve this easily? (I'm always wondering why std::map does not include a member function for us to do so.)

  Read the article

• How should I get Xcode to link an iOS project that uses a C++ static library

  - by user1681572

  Using Xcode, I've written a Cocoa Touch static library, mainly in C++. It exposes a C interface for the benefit of Objective-C client code. I have a client iOS app that uses it, and everything works and runs as expected, except that I found I needed to include a minimal .cpp file in the client project to get the link to succeed. Otherwise I get C++-related unresolved symbols, e.g. operator new(unsigned long). The above hack is easy and effective, and so I guess I'm not breaking any laws, but is there a proper way to eliminate my linker errors?

  Read the article

• Method overloading in groovy

  - by slojo

  I am trying to take advantage of the convenience of groovy's scripting syntax to assign properties, but having trouble with a specific case. I must be missing something simple here. I define class A, B, C as so: class A { A() { println "Constructed class A!" } } class B { B() { println "Constructed class B!" } } class C { private member C() { println "Constructed class C!" } def setMember(A a) { println "Called setMember(A)!" member = a } def setMember(B b) { println "Called setMember(B)!" member = b } } And then try the following calls in a script: c = new C() c.setMember(new A()) // works c.member = new A() // works c.setMember(new B()) // works c.member = new B() // doesn't work! The last assignment results in an error: 'Cannot cast object of class B to class A". Why doesn't it call the proper setMember method for class B like it does for class A?

  Read the article

• Is it possible to have a variadic function in C with no non-variadic parameter?

  - by Tim

  I have the following function: void doStuff(int unusedParameter, ...) { va_list params; va_start(params, unusedParameter); /* ... */ va_end(params); } As part of a refactor, I'd like to remove the unused parameter without otherwise changing the implementation of the function. As far as I can tell, it's impossible to use va_start when you don't have a last non-variadic parameter to refer to. Is there any way around this? Background: It is in fact a C++ program, so I could use some operator-overloading magic as suggested here, but I was hoping not to have to change the interface at this point. The existing function does its work by requiring that the variable argument list be null-terminated, and scanning for the NULL, therefore it doesn't need a leading argument to tell it how many arguments it has.

  Read the article

• C++/CLI and C#, "Casting" Functions to Delegates, What's the scoop?

  - by Jacob G

  In C# 2.0, I can do the following: public class MyClass { delegate void MyDelegate(int myParam); public MyClass(OtherObject obj) { //THIS IS THE IMPORTANT PART obj.SomeCollection.Add((MyDelegate)MyFunction); } private void MyFunction(int myParam); { //... } } Trying to implement the same thing in C++/CLI, it appears I have to do: MyDelegate del = gcnew MyDelegate(this, MyFunction); obj-SomeCollection-Add(del); Obviously I can create a new instance of the delegate in C# as well instead of what's going on up there. Is there some kind of magic going on in the C# world that doesn't exist in C++/CLI that allows that cast to work? Some kind of magic anonymous delegate? Thanks.

  Read the article

• Serialized object in intent returning as String

  - by B_

  In my application, I am trying to pass a serializable object through an intent to another activity. The intent is not entirely created by me, it is created and passed through a search suggestion. In the content provider for the search suggestion, the object is created and placed in the SUGGEST_COLUMN_INTENT_EXTRA_DATA column of the MatrixCursor. However, when in the receiving activity I call getIntent().getSerializableExtra(SearchManager.EXTRA_DATA_KEY), the returned object is of type String and I cannot cast it into the original object class. I tried making a parcelable wrapper for my object that calls out.writeSerializable(...) and use that instead but the same thing happened. The string that is returned is like a generic Object toString(), i.e. com.foo.yak.MyAwesomeClass@4350058, so I'm assuming that toString() is being called somewhere where I have no control. Hopefully I'm just missing something simple. Thanks for the help!

  Read the article

• How do I do division on HH:MM:SS format time strings in C#?

  - by Jake

  I have a series of times that are coming to me as strings from a web service. The times are formated as HH:MM:SS:000 (3 milisecond digits). I need to compare two times to determine if one is more than twice as long as the other: if ( timeA / timeB > 2 ) What's the simplest way to work with the time strings? If I was writing in Python this would be the answer to my question: Difference between two time intervals in Python Edit: What I'm really looking for is a way to get the ratio of timeA to timeB, which requires division, not subtraction. Unfortunately, the DateTime structure doesn't appear to have a division operator. Updated the question title to reflect this.

  Read the article

• Asp.Net - Can a LinkButton.CommandArgument be typed?

  - by Stimul8d

  Okay so given a LinkButton inside a the ItemTemplate of a Repeater declared like this - <asp:LinkButton ID="restrictionDelete" runat="server" CssClass="restrictionDelete" Text="Delete..." OnCommand="lnkDeleteRestriction_Command" CommandName="Delete" CommandArgument="<%# Container.DataItem %>"></asp:LinkButton> Now,..the repeater is being bound to a list of Restriction objects so when the lnkDeleteRestriction_Command is fired I'm expecting that I can cast the CommandEventArgs.CommandArgument which is an object to my Restriction type. This doesn't seem to be so,..I just get the fully qualified type name as a string. Can I receive a typed command argument at all and if not, why is it an object? Thanks in advance,

  Read the article

• c# 4.0 - best way to refactor a block of "If (something is Type) {}" statements?

  - by Andrew Johns

  I've got some code that looks like this, public void ResetControls(Control controlOnPage) { if (controlOnPage is TextBox) { ResetTextBoxControl(controlOnPage); } if (controlOnPage is MediaPicker) { ((MediaPicker)controlOnPage).Media = null; } if (controlOnPage is RelatedContentPicker) { ((RelatedContentPicker)controlOnPage).RelatedContentCollection = null; } ... ... foreach (Control child in controlOnPage.Controls) { ResetControls(child); } } The idea behind it is that I can pass a page to the method and it'll recursively reset all the controls on it to their default states - in the case of MediaPicker and RelatedContentPicker, these are user controls that I've created. FXCop warns me "Do Not Cast Unnecessarily" for this code - but I'm unsure how to rewrite it to make it better. Any ideas?

  Read the article

• In SQL how do I get the maximum value for an integer?

  - by CoffeeMonster

  Hi, I am trying to find out the maximum value for an integer (signed or unsigned) from a MySQL database. Is there a way to pull back this information from the database itself? Are there any built-in constants or functions I can use (either standard SQL or MySQL specific). At http://dev.mysql.com/doc/refman/5.0/en/numeric-types.html it lists the values - but is there a way for the database to tell me. The following gives me the MAX_BIGINT - what I'd like is the MAX_INT. SELECT CAST( 99999999999999999999999 AS SIGNED ) as max_int; # max_int | 9223372036854775807 Thanks in advance,

  Read the article

< Previous Page | 150 151 152 153 154 155 156 157 158 159 160 161  | Next Page >