Search Results

Search found 17884 results on 716 pages for 'column types'.

Page 62/716 | < Previous Page | 58 59 60 61 62 63 64 65 66 67 68 69  | Next Page >

  • C++ stack for multiple data types (RPN vector calculator)

    - by Arrieta
    Hello: I have designed a quick and basic vector arithmetic library in C++. I call the program from the command line when I need a rapid cross product, or angle between vectors. I don't use Matlab or Octave or related, because the startup time is larger than the computation time. Again, this is for very basic operations. I am extending this program, and I will make it work as an RPN calculator, for operations of the type: 1 2 3 4 5 6 x out: -3 6 -3 (give one vector, another vector, and the "cross" operator; spit out the cross product) The stack must accept 3d vectors or scalars, for operations like: 1 2 3 2 * out: 2 4 6 The lexer and parser for this mini-calculator are trivial, but I cannot seem to think of a good way for creating the internal stack. How would you create a stack of for containing vectors or doubles (I rolled up my own very simple vector class - less than one hundred lines and it does everything I need). How can I create a simple stack which accepts elements of class Vector or type double? Thank you.

    Read the article

  • Return/consume dynamic anonymous type across assembly boundaries

    - by friism
    The code below works great. If the Get and Use methods are in different assemblies, the code fails with a RuntimeBinderException. This is because the .Net runtime system only guarantees commonality of anonymous types (<string, int> in this case) within assemblies. Is there any way to fool the runtime system to overcome this? I can expect the object in the debugger on the Use side, and the debugger can see the relevant properties. class Program { static void Main(string[] args) { UsePerson(); Console.ReadLine(); } public static void UsePerson() { var person = GetPerson(); Console.WriteLine(person.Name); } public static dynamic GetPerson() { return new { Name = "Foo", Age = 30 }; } }

    Read the article

  • CollectionViewSource & Selective Column Display

    - by Berryl
    By selective column display i mean the following: a control shows a listing of widgets (WidgetVm.DisplayName), with the default display name being in English (WidgetVm.EnglishName), but with the option to show the widget in French (WidgetVm.FrenchName). There also sorting and filtering available, which is why CollectionViewSource seems ideal. I know you can have multiple views over the same source but I haven't figured out how to do this yet. Is that the right approach to solving this? How? Cheers, Berryl

    Read the article

  • WCF passing data types

    - by Jonathan D
    writing a WCF soap server which is going to be working with a flex client. what the best way of passing the result of a sql select statement? with pro's and con's would be good :D I know I can define data contracts, however defining lots of these for every sql statment is going to take a long time. i'm doing this with SQL server 2000, VS2010 and flex sdk 3/4. apart form that there isn't really that many other requirements that couldn't be moved at present. Thanks for the help

    Read the article

  • Create a Cumulative Sum Column in MySQL

    - by Kirk
    I have a table that looks like this: id count 1 100 2 50 3 10 I want to add a new column called cumulative_sum, so the table would look like this: id count cumulative_sum 1 100 100 2 50 150 3 10 160 Is there a MySQL update statement that can do this easily? What's the best way to accomplish this?

    Read the article

  • "Inherited" types using CRTP and typedef

    - by Ken Moynihan
    The following code does not compile. I get an error message: error C2039: 'Asub' : is not a member of 'C' Can someone help me to understand this? Tried VS2008 & 2010 compiler. template <class T> class B { typedef int Asub; public: void DoSomething(typename T::Asub it) { } }; class C : public B<C> { public: typedef int Asub; }; class A { public: typedef int Asub; }; int _tmain(int argc, _TCHAR* argv[]) { C theThing; theThing.DoSomething(C::Asub()); return 0; }

    Read the article

  • C# reference collection for storing reference types

    - by ivo s
    I like to implement a collection (something like List<T>) which would hold all my objects that I have created in the entire life span of my application as if its an array of pointers in C++. The idea is that when my process starts I can use a central factory to create all objects and then periodically validate/invalidate their state. Basically I want to make sure that my process only deals with valid instances and I don't re-fetch information I already fetched from the database. So all my objects will basically be in one place - my collection. A cool thing I can do with this is avoid database calls to get data from the database if I already got it (even if I updated it after retrieval its still up-to-date if of course some other process didn't update it but that a different concern). I don't want to be calling new Customer("James Thomas"); again if I initted James Thomas already sometime in the past. Currently I will end up with multiple copies of the same object across the appdomain - some out of sync other in sync and even though I deal with this using timestamp field on the MSSQL server I'd like to keep only one copy per customer in my appdomain (if possible process would be better). I can't use regular collections like List or ArrayList for example because I cannot pass parameters by their real local reference to the their existing Add() methods where I'm creating them using ref so that's not to good I think. So how can this be implemented/can it be implemented at all ? A 'linked list' type of class with all methods working with ref & out params is what I'm thinking now but it may get ugly pretty quickly. Is there another way to implement such collection like RefList<T>.Add(ref T obj)? So bottom line is: I don't want re-create an object if I've already created it before during the entire application life unless I decide to re-create it explicitly (maybe its out-of-date or something so I have to fetch it again from the db). Is there alternatives maybe ?

    Read the article

  • Correct way to detect sequence parameter?

    - by noamtm
    I want to write a function that accepts a parameter which can be either a sequence or a single value. The type of value is str, int, etc., but I don't want it to be restricted to a hardcoded list. In other words, I want to know if the parameter X is a sequence or something I have to convert to a sequence to avoid special-casing later. I could do type(X) in (list, tuple) but there may be other sequence types I'm not aware of, and no common base class. -N. Edit: See my "answer" below for why most of these answers don't help me. Maybe you have something better to suggest.

    Read the article

  • Finding a certain cell in gridview through the use of column and row

    - by newName
    I have a populated gridview that consist of template fields. I would like to find/check a certain number of cells using values of rows and columns. Eg: |Time|col1|col2|col3|col4|col5| |1200|------|-----|-----|------|-----| |1300|------| -X- |-----|------|-----| |1400|------|-----|-----|------|-----| lets say i have the value "1300" for the row and the column header text "col2", I would like to find the cell marked "X" and check for some condition and change the text if necessary (col1 - col5 are template fields made up of labels and buttons, so therefore base on certain conditions i would like to show/hide the labels/buttons or change the text for the labels) Thanks

    Read the article

  • Boost::Serialization Mpi Sending array of user defined types

    - by Noman Javed
    I want to send my Array class using boost Mpi template class Array { private: int size; T* data; public: // constructors + other stuff }; Here T can be any built in type or user defined type. Suppose I have a class complex struct complex { std::vector real_imag; // contain two elements }; So the question is how can I send Array using Boost::Mpi + serialization. Thanks in anticipation Regards Noman

    Read the article

  • WCF DataContract deserialization of complex types

    - by Meidan Alon
    Hi, I have a service that returns a collection of MyClass objects. If all of the MyClass instances have null in MyClass2Reference then everything works fine. Otherwise, I get a "Connection reset" error on the client side. What am I doing wrong? Nevrmind: was a problem with NHibernate lazy proxy objects. [DataContract] public MyClass { [DataMember] int ID; [DataMember] MyClass2 MyClass2Reference; } [DataContract] public MyClass2 { [DataMember] int ID; [DataMember] string Name; }

    Read the article

  • Nullables? Detecting them

    - by Aren B
    Ok, im still a bit new to using nullable types. I'm writing a reflecting object walker for a project of mine, im getting to the point where im setting the value of a reflected property with the value i've retrieved from a reflected property. The value i've retrieved is still in object form, and it dawned on me, since i want my object walker to return null when it can't find something, (I thought about throwing an exception, but i want this to soft-fail when something's wrong). Anyway, some of the values im setting/getting are decimal bool etc... so it dawned on me that i should just NOT set a non-nullable value, but I realized I straight up don't know how to tell decimal from decimal? Is it enough to key on if the Type of the property im setting is inherited from ValueType?

    Read the article

  • Templated << friend not working when in interrelationship with other templated union types

    - by Dwight
    While working on my basic vector library, I've been trying to use a nice syntax for swizzle-based printing. The problem occurs when attempting to print a swizzle of a different dimension than the vector in question. In GCC 4.0, I originally had the friend << overloaded functions (with a body, even though it duplicated code) for every dimension in each vector, which caused the code to work, even if the non-native dimension code never actually was called. This failed in GCC 4.2. I recently realized (silly me) that only the function declaration was needed, not the body of the code, so I did that. Now I get the same warning on both GCC 4.0 and 4.2: LINE 50 warning: friend declaration 'std::ostream& operator<<(std::ostream&, const VECTOR3<TYPE>&)' declares a non-template function Plus the five identical warnings more for the other function declarations. The below example code shows off exactly what's going on and has all code necessary to reproduce the problem. #include <iostream> // cout, endl #include <sstream> // ostream, ostringstream, string using std::cout; using std::endl; using std::string; using std::ostream; // Predefines template <typename TYPE> union VECTOR2; template <typename TYPE> union VECTOR3; template <typename TYPE> union VECTOR4; typedef VECTOR2<float> vec2; typedef VECTOR3<float> vec3; typedef VECTOR4<float> vec4; template <typename TYPE> union VECTOR2 { private: struct { TYPE x, y; } v; struct s1 { protected: TYPE x, y; }; struct s2 { protected: TYPE x, y; }; struct s3 { protected: TYPE x, y; }; struct s4 { protected: TYPE x, y; }; struct X : s1 { operator TYPE() const { return s1::x; } }; struct XX : s2 { operator VECTOR2<TYPE>() const { return VECTOR2<TYPE>(s2::x, s2::x); } }; struct XXX : s3 { operator VECTOR3<TYPE>() const { return VECTOR3<TYPE>(s3::x, s3::x, s3::x); } }; struct XXXX : s4 { operator VECTOR4<TYPE>() const { return VECTOR4<TYPE>(s4::x, s4::x, s4::x, s4::x); } }; public: VECTOR2() {} VECTOR2(const TYPE& x, const TYPE& y) { v.x = x; v.y = y; } X x; XX xx; XXX xxx; XXXX xxxx; // Overload for cout friend ostream& operator<<(ostream& os, const VECTOR2<TYPE>& toString) { os << "(" << toString.v.x << ", " << toString.v.y << ")"; return os; } friend ostream& operator<<(ostream& os, const VECTOR3<TYPE>& toString); friend ostream& operator<<(ostream& os, const VECTOR4<TYPE>& toString); }; template <typename TYPE> union VECTOR3 { private: struct { TYPE x, y, z; } v; struct s1 { protected: TYPE x, y, z; }; struct s2 { protected: TYPE x, y, z; }; struct s3 { protected: TYPE x, y, z; }; struct s4 { protected: TYPE x, y, z; }; struct X : s1 { operator TYPE() const { return s1::x; } }; struct XX : s2 { operator VECTOR2<TYPE>() const { return VECTOR2<TYPE>(s2::x, s2::x); } }; struct XXX : s3 { operator VECTOR3<TYPE>() const { return VECTOR3<TYPE>(s3::x, s3::x, s3::x); } }; struct XXXX : s4 { operator VECTOR4<TYPE>() const { return VECTOR4<TYPE>(s4::x, s4::x, s4::x, s4::x); } }; public: VECTOR3() {} VECTOR3(const TYPE& x, const TYPE& y, const TYPE& z) { v.x = x; v.y = y; v.z = z; } X x; XX xx; XXX xxx; XXXX xxxx; // Overload for cout friend ostream& operator<<(ostream& os, const VECTOR3<TYPE>& toString) { os << "(" << toString.v.x << ", " << toString.v.y << ", " << toString.v.z << ")"; return os; } friend ostream& operator<<(ostream& os, const VECTOR2<TYPE>& toString); friend ostream& operator<<(ostream& os, const VECTOR4<TYPE>& toString); }; template <typename TYPE> union VECTOR4 { private: struct { TYPE x, y, z, w; } v; struct s1 { protected: TYPE x, y, z, w; }; struct s2 { protected: TYPE x, y, z, w; }; struct s3 { protected: TYPE x, y, z, w; }; struct s4 { protected: TYPE x, y, z, w; }; struct X : s1 { operator TYPE() const { return s1::x; } }; struct XX : s2 { operator VECTOR2<TYPE>() const { return VECTOR2<TYPE>(s2::x, s2::x); } }; struct XXX : s3 { operator VECTOR3<TYPE>() const { return VECTOR3<TYPE>(s3::x, s3::x, s3::x); } }; struct XXXX : s4 { operator VECTOR4<TYPE>() const { return VECTOR4<TYPE>(s4::x, s4::x, s4::x, s4::x); } }; public: VECTOR4() {} VECTOR4(const TYPE& x, const TYPE& y, const TYPE& z, const TYPE& w) { v.x = x; v.y = y; v.z = z; v.w = w; } X x; XX xx; XXX xxx; XXXX xxxx; // Overload for cout friend ostream& operator<<(ostream& os, const VECTOR4& toString) { os << "(" << toString.v.x << ", " << toString.v.y << ", " << toString.v.z << ", " << toString.v.w << ")"; return os; } friend ostream& operator<<(ostream& os, const VECTOR2<TYPE>& toString); friend ostream& operator<<(ostream& os, const VECTOR3<TYPE>& toString); }; // Test code int main (int argc, char * const argv[]) { vec2 my2dVector(1, 2); cout << my2dVector.x << endl; cout << my2dVector.xx << endl; cout << my2dVector.xxx << endl; cout << my2dVector.xxxx << endl; vec3 my3dVector(3, 4, 5); cout << my3dVector.x << endl; cout << my3dVector.xx << endl; cout << my3dVector.xxx << endl; cout << my3dVector.xxxx << endl; vec4 my4dVector(6, 7, 8, 9); cout << my4dVector.x << endl; cout << my4dVector.xx << endl; cout << my4dVector.xxx << endl; cout << my4dVector.xxxx << endl; return 0; } The code WORKS and produces the correct output, but I prefer warning free code whenever possible. I followed the advice the compiler gave me (summarized here and described by forums and StackOverflow as the answer to this warning) and added the two things that supposedly tells the compiler what's going on. That is, I added the function definitions as non-friends after the predefinitions of the templated unions: template <typename TYPE> ostream& operator<<(ostream& os, const VECTOR2<TYPE>& toString); template <typename TYPE> ostream& operator<<(ostream& os, const VECTOR3<TYPE>& toString); template <typename TYPE> ostream& operator<<(ostream& os, const VECTOR4<TYPE>& toString); And, to each friend function that causes the issue, I added the <> after the function name, such as for VECTOR2's case: friend ostream& operator<< <> (ostream& os, const VECTOR3<TYPE>& toString); friend ostream& operator<< <> (ostream& os, const VECTOR4<TYPE>& toString); However, doing so leads to errors, such as: LINE 139: error: no match for 'operator<<' in 'std::cout << my2dVector.VECTOR2<float>::xxx' What's going on? Is it something related to how these templated union class-like structures are interrelated, or is it due to the unions themselves? Update After rethinking the issues involved and listening to the various suggestions of Potatoswatter, I found the final solution. Unlike just about every single cout overload example on the internet, I don't need access to the private member information, but can use the public interface to do what I wish. So, I make a non-friend overload functions that are inline for the swizzle parts that call the real friend overload functions. This bypasses the issues the compiler has with templated friend functions. I've added to the latest version of my project. It now works on both versions of GCC I tried with no warnings. The code in question looks like this: template <typename SWIZZLE> inline typename EnableIf< Is2D< typename SWIZZLE::PARENT >, ostream >::type& operator<<(ostream& os, const SWIZZLE& printVector) { os << (typename SWIZZLE::PARENT(printVector)); return os; } template <typename SWIZZLE> inline typename EnableIf< Is3D< typename SWIZZLE::PARENT >, ostream >::type& operator<<(ostream& os, const SWIZZLE& printVector) { os << (typename SWIZZLE::PARENT(printVector)); return os; } template <typename SWIZZLE> inline typename EnableIf< Is4D< typename SWIZZLE::PARENT >, ostream >::type& operator<<(ostream& os, const SWIZZLE& printVector) { os << (typename SWIZZLE::PARENT(printVector)); return os; }

    Read the article

  • Any way to automatically wrap comments at column 80 in Visual Studio 2008? ..or display where column

    - by Jon Cage
    Is there any way to automatically wrap comments at the 80-column boundary as you type them? ..or failing that, any way to display a faint line at the coulmn 80 boundary to make wrapping them manually a little easier? Several other IDEs I use have one or other of those functions and it makes writing comments that wrap in sensible places much easier/quicker. [Edit] If (like me) you're using Visual C++ Express, you need to change the VisualStudio part of the key into VCExpress - had me confused for a while there!

    Read the article

  • SQL How to join multiplue columns with same name to one column

    - by Choi Shun Chi
    There is a super class account {User, TYPE} and subclasses saving{User, ID, balance,TYPE,interest,curency_TYPE} time{User,ID,balance,TYPE,interest,curency_TYPE,start_date,due_date,period} fore{User,ID,balance,interest,curency_TYPE} User and TYPE is the primary key of account and foreign key of three subclasses ID is primary key of three subclasses how to make a list of showing all IDs in one column?Also the same as balance and TYPE meet the problem I considered a.ID as saving, b.ID as time but it showing them separately

    Read the article

  • Types in Python - Google Appengine

    - by Chris M
    Getting a bit peeved now; I have a model and a class thats just storing a get request in the database; basic tracking. class SearchRec(db.Model): WebSite = db.StringProperty()#required=True WebPage = db.StringProperty() CountryNM = db.StringProperty() PrefMailing = db.BooleanProperty() DateStamp = db.DateTimeProperty(auto_now_add=True) IP = db.StringProperty() class AddSearch(webapp.RequestHandler): def get(self): searchRec = SearchRec() searchRec.WebSite = self.request.get('WEBSITE') searchRec.WebPage = self.request.get('WEBPAGE') searchRec.CountryNM = self.request.get('COUNTRY') searchRec.PrefMailing = bool(self.request.get('MAIL')) searchRec.IP = self.request.get('IP') Bool has my biscuit; I thought that setting bool(self.reque....) would set the type of the string but no matter what I pass it it still stores it as TRUE in the database. I had the same issue with using required=True on strings for the model; the damn thing kept saying that nothing was being passed... but it had. Ta

    Read the article

  • ATL and types from scrrun.dll

    - by MaxFX
    Hello. I have interface in ATL project which must contains member with parameter of Scripting::IDictionary** but in MIDL file with description of my interface it's not possible because Scripting library is not presented in default library. I always have scrrun.tlb and trying to use it in MIDL but it's not work Code is here: midl-code

    Read the article

  • How to get column value into row header

    - by Dharmendra Mohapatra
    ID amount year 1 300 02-02-2010 00:00 2 400 02-02-2009 00:00 3 200 02-02-2011 00:00 4 300 22-02-2010 00:00 5 400 12-02-2009 00:00 6 500 22-02-2009 00:00 7 600 02-02-2006 00:00 8 700 02-07-2012 00:00 9 500 08-02-2012 00:00 10 800 09-02-2011 00:00 11 500 06-02-2010 00:00 12 600 01-02-2011 00:00 13 300 02-02-2019 00:00 Desired output Y1 Y2 Y3 ........... sum(amount) sum(amount) sum(amount) Please suggest a approach Y1 is the year part of the date so my result column would be 2006 2009 2010 2011 2012 600 1300 800 1900 1200 Thanks. DB- MYSQL, SQL SERVER Thanks.

    Read the article

< Previous Page | 58 59 60 61 62 63 64 65 66 67 68 69  | Next Page >