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  • Confused Why I am getting C1010 error?

    - by bluepixel
    I have three files: Main, slist.h and slist.cpp can be seen at http://forums.devarticles.com/c-c-help-52/confused-why-i-am-getting-c2143-and-c1010-error-259574.html I'm trying to make a program where main reads the list of student names from a file (roster.txt) and inserts all the names in a list in ascending order. This is the full class roster list (notCheckedIN). From here I will read all students who have come to write the exams, each checkin will transfer their name to another list (in ascending order) called present. The final product is notCheckedIN will contain a list of all those students that did not write the exam and present will contain the list of all students who wrote the exam Main File: // Exam.cpp : Defines the entry point for the console application. #include "stdafx.h" #include "iostream" #include "iomanip" #include "fstream" #include "string" #include "slist.h" using namespace std; void OpenFile(ifstream&); void GetClassRoster(SortList&, ifstream&); void InputStuName(SortList&, SortList&); void UpdateList(SortList&, SortList&, string); void Print(SortList&, SortList&); const string END_DATA = "EndData"; int main() { ifstream roster; SortList notCheckedIn; //students present SortList present; //student absent OpenFile(roster); if(!roster) //Make sure file is opened return 1; GetClassRoster(notCheckedIn, roster); //insert the roster list into the notCheckedIn list InputStuName(present, notCheckedIn); Print(present, notCheckedIn); return 0; } void OpenFile(ifstream& roster) //Precondition: roster is pointing to file containing student anmes //Postcondition:IF file does not exist -> exit { string fileName = "roster.txt"; roster.open(fileName.c_str()); if(!roster) cout << "***ERROR CANNOT OPEN FILE :"<< fileName << "***" << endl; } void GetClassRoster(SortList& notCheckedIN, ifstream& roster) //Precondition:roster points to file containing list of student last name // && notCheckedIN is empty //Postcondition:notCheckedIN is filled with the names taken from roster.txt in ascending order { string name; roster >> name; while(roster) { notCheckedIN.Insert(name); roster >> name; } } void InputStuName(SortList& present, SortList& notCheckedIN) //Precondition: present list is empty initially and notCheckedIN list is full //Postcondition: repeated prompting to enter stuName // && notCheckedIN will delete all names found in present // && present will contain names present // && names not found in notCheckedIN will report Error { string stuName; cout << "Enter last name (Enter EndData if none to Enter): "; cin >> stuName; while(stuName!=END_DATA) { UpdateList(present, notCheckedIN, stuName); } } void UpdateList(SortList& present, SortList& notCheckedIN, string stuName) //Precondition:stuName is assigned //Postcondition:IF stuName is present, stuName is inserted in present list // && stuName is removed from the notCheckedIN list // ELSE stuName does not exist { if(notCheckedIN.isPresent(stuName)) { present.Insert(stuName); notCheckedIN.Delete(stuName); } else cout << "NAME IS NOT PRESENT" << endl; } void Print(SortList& present, SortList& notCheckedIN) //Precondition: present and notCheckedIN contains a list of student Names present/not present //Postcondition: content of present and notCheckedIN is printed { cout << "Candidates Present" << endl; present.Print(); cout << "Candidates Absent" << endl; notCheckedIN.Print(); } Header File: //Specification File: slist.h //This file gives the specifications of a list abstract data type //List items inserted will be in order //Class SortList, structured type used to represent an ADT using namespace std; const int MAX_LENGTH = 200; typedef string ItemType; //Class Object (class instance) SortList. Variable of class type. class SortList { //Class Member - components of a class, can be either data or functions public: //Constructor //Post-condition: Empty list is created SortList(); //Const member function. Compiler error occurs if any statement within tries to modify a private data bool isEmpty() const; //Post-condition: == true if list is empty // == false if list is not empty bool isFull() const; //Post-condition: == true if list is full // == false if list is full int Length() const; //Post-condition: size of list void Insert(ItemType item); //Precondition: NOT isFull() && item is assigned //Postcondition: item is in list && Length() = Length()@entry + 1 void Delete(ItemType item); //Precondition: NOT isEmpty() && item is assigned //Postcondition: // IF items is in list at entry // first occurance of item in list is removed // && Length() = Length()@entry -1; // ELSE // list is not changed bool isPresent(ItemType item) const; //Precondition: item is assigned //Postcondition: == true if item is present in list // == false if item is not present in list void Print() const; //Postcondition: All component of list have been output private: int length; ItemType data[MAX_LENGTH]; void BinSearch(ItemType, bool&, int&) const; }; Source File: //Implementation File: slist.cpp //This file gives the specifications of a list abstract data type //List items inserted will be in order //Class SortList, structured type used to represent an ADT #include "iostream" #include "slist.h" using namespace std; // int length; // ItemType data[MAX_SIZE]; //Class Object (class instance) SortList. Variable of class type. SortList::SortList() //Constructor //Post-condition: Empty list is created { length=0; } //Const member function. Compiler error occurs if any statement within tries to modify a private data bool SortList::isEmpty() const //Post-condition: == true if list is empty // == false if list is not empty { return(length==0); } bool SortList::isFull() const //Post-condition: == true if list is full // == false if list is full { return (length==(MAX_LENGTH-1)); } int SortList::Length() const //Post-condition: size of list { return length; } void SortList::Insert(ItemType item) //Precondition: NOT isFull() && item is assigned //Postcondition: item is in list && Length() = Length()@entry + 1 // && list componenet are in ascending order of value { int index; index = length -1; while(index >=0 && item<data[index]) { data[index+1]=data[index]; index--; } data[index+1]=item; length++; } void SortList:elete(ItemType item) //Precondition: NOT isEmpty() && item is assigned //Postcondition: // IF items is in list at entry // first occurance of item in list is removed // && Length() = Length()@entry -1; // && list components are in ascending order // ELSE data array is unchanged { bool found; int position; BinSearch(item,found,position); if (found) { for(int index = position; index < length; index++) data[index]=data[index+1]; length--; } } bool SortList::isPresent(ItemType item) const //Precondition: item is assigned && length <= MAX_LENGTH && items are in ascending order //Postcondition: true if item is found in the list // false if item is not found in the list { bool found; int position; BinSearch(item,found,position); return (found); } void SortList::Print() const //Postcondition: All component of list have been output { for(int x= 0; x<length; x++) cout << data[x] << endl; } void SortList::BinSearch(ItemType item, bool found, int position) const //Precondition: item contains item to be found // && item in the list is an ascending order //Postcondition: IF item is in list, position is returned // ELSE item does not exist in the list { int first = 0; int last = length -1; int middle; found = false; while(!found) { middle = (first+last)/2; if(data[middle]<item) first = middle+1; else if (data[middle] > item) last = middle -1; else found = true; } if(found) position = middle; } I cannot get rid of the C1010 error: fatal error C1010: unexpected end of file while looking for precompiled header. Did you forget to add '#include "stdafx.h"' to your source? Is there a way to get rid of this error? When I included "stdafx.h" I received the following 32 errors (which does not make sense to me why because I referred back to my manual on how to use Class method - everything looks a.ok.) Error 1 error C2871: 'std' : a namespace with this name does not exist c:\..\slist.h 6 Error 2 error C2146: syntax error : missing ';' before identifier 'ItemType' c:\..\slist.h 8 Error 3 error C4430: missing type specifier - int assumed. Note: C++ does not support default-int c:\..\slist.h 8 Error 4 error C4430: missing type specifier - int assumed. Note: C++ does not support default-int c:\..\slist.h 8 Error 5 error C2061: syntax error : identifier 'ItemType' c:\..\slist.h 30 Error 6 error C2061: syntax error : identifier 'ItemType' c:\..\slist.h 34 Error 7 error C2061: syntax error : identifier 'ItemType' c:\..\slist.h 43 Error 8 error C2146: syntax error : missing ';' before identifier 'data' c:\..\slist.h 52 Error 9 error C4430: missing type specifier - int assumed. Note: C++ does not support default-int c:\..\slist.h 52 Error 10 error C4430: missing type specifier - int assumed. Note: C++ does not support default-int c:\..\slist.h 52 Error 11 error C2061: syntax error : identifier 'ItemType' c:\..\slist.h 53 Error 12 error C2146: syntax error : missing ')' before identifier 'item' c:\..\slist.cpp 41 Error 13 error C2761: 'void SortList::Insert(void)' : member function redeclaration not allowed c:\..\slist.cpp 41 Error 14 error C2059: syntax error : ')' c:\..\slist.cpp 41 Error 15 error C2143: syntax error : missing ';' before '{' c:\..\slist.cpp 45 Error 16 error C2447: '{' : missing function header (old-style formal list?) c:\..\slist.cpp 45 Error 17 error C2146: syntax error : missing ')' before identifier 'item' c:\..\slist.cpp 57 Error 18 error C2761: 'void SortList:elete(void)' : member function redeclaration not allowed c:\..\slist.cpp 57 Error 19 error C2059: syntax error : ')' c:\..\slist.cpp 57 Error 20 error C2143: syntax error : missing ';' before '{' c:\..\slist.cpp 65 Error 21 error C2447: '{' : missing function header (old-style formal list?) c:\..\slist.cpp 65 Error 22 error C2146: syntax error : missing ')' before identifier 'item' c:\..\slist.cpp 79 Error 23 error C2761: 'bool SortList::isPresent(void) const' : member function redeclaration not allowed c:\..\slist.cpp 79 Error 24 error C2059: syntax error : ')' c:\..\slist.cpp 79 Error 25 error C2143: syntax error : missing ';' before '{' c:\..\slist.cpp 83 Error 26 error C2447: '{' : missing function header (old-style formal list?) c:\..\slist.cpp 83 Error 27 error C2065: 'data' : undeclared identifier c:\..\slist.cpp 95 Error 28 error C2146: syntax error : missing ')' before identifier 'item' c:\..\slist.cpp 98 Error 29 error C2761: 'void SortList::BinSearch(void) const' : member function redeclaration not allowed c:\..\slist.cpp 98 Error 30 error C2059: syntax error : ')' c:\..\slist.cpp 98 Error 31 error C2143: syntax error : missing ';' before '{' c:\..\slist.cpp 103 Error 32 error C2447: '{' : missing function header (old-style formal list?) c:\..\slist.cpp 103

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  • Getting time in ubuntu

    - by user2578666
    include #include <stdio.h> int GetTime() { struct timespec tsp; clock_gettime(CLOCK_REALTIME, &tsp); //Call clock_gettime to fill tsp fprintf(stdout, "time=%d.%d\n", tsp.tv_sec, tsp.tv_nsec); fflush(stdout); } I am trying to compile the above code but it keeps throwing the error: time.c: In function ‘GetTime’: time.c:12:4: warning: implicit declaration of function ‘clock_gettime’ [-Wimplicit-function-declaration] time.c:12:18: error: ‘CLOCK_REALTIME’ undeclared (first use in this function) time.c:12:18: note: each undeclared identifier is reported only once for each function it appears in time.c:14:4: warning: format ‘%d’ expects argument of type ‘int’, but argument 3 has type ‘__time_t’ [-Wformat] time.c:14:4: warning: format ‘%d’ expects argument of type ‘int’, but argument 4 has type ‘long int’ [-Wformat] I have tried compiling with -lrt flag and -std=gnu99. Nothing works.

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  • texture mapping with lib3ds and SOIL help

    - by Adam West
    I'm having trouble with my project for loading a texture map onto a model. Any insight into what is going wrong with my code is fantastic. Right now the code only renders a teapot which I have assinged after creating it in 3DS Max. 3dsloader.cpp #include "3dsloader.h" Object::Object(std:: string filename) { m_TotalFaces = 0; m_model = lib3ds_file_load(filename.c_str()); // If loading the model failed, we throw an exception if(!m_model) { throw strcat("Unable to load ", filename.c_str()); } // set properties of texture coordinate generation for both x and y coordinates glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_EYE_LINEAR); glTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_EYE_LINEAR); // if not already enabled, enable texture generation if(! glIsEnabled(GL_TEXTURE_GEN_S)) glEnable(GL_TEXTURE_GEN_S); if(! glIsEnabled(GL_TEXTURE_GEN_T)) glEnable(GL_TEXTURE_GEN_T); } Object::~Object() { if(m_model) // if the file isn't freed yet lib3ds_file_free(m_model); //free up memory glDisable(GL_TEXTURE_GEN_S); glDisable(GL_TEXTURE_GEN_T); } void Object::GetFaces() { m_TotalFaces = 0; Lib3dsMesh * mesh; // Loop through every mesh. for(mesh = m_model->meshes;mesh != NULL;mesh = mesh->next) { // Add the number of faces this mesh has to the total number of faces. m_TotalFaces += mesh->faces; } } void Object::CreateVBO() { assert(m_model != NULL); // Calculate the number of faces we have in total GetFaces(); // Allocate memory for our vertices and normals Lib3dsVector * vertices = new Lib3dsVector[m_TotalFaces * 3]; Lib3dsVector * normals = new Lib3dsVector[m_TotalFaces * 3]; Lib3dsTexel* texCoords = new Lib3dsTexel[m_TotalFaces * 3]; Lib3dsMesh * mesh; unsigned int FinishedFaces = 0; // Loop through all the meshes for(mesh = m_model->meshes;mesh != NULL;mesh = mesh->next) { lib3ds_mesh_calculate_normals(mesh, &normals[FinishedFaces*3]); // Loop through every face for(unsigned int cur_face = 0; cur_face < mesh->faces;cur_face++) { Lib3dsFace * face = &mesh->faceL[cur_face]; for(unsigned int i = 0;i < 3;i++) { memcpy(&texCoords[FinishedFaces*3 + i], mesh->texelL[face->points[ i ]], sizeof(Lib3dsTexel)); memcpy(&vertices[FinishedFaces*3 + i], mesh->pointL[face->points[ i ]].pos, sizeof(Lib3dsVector)); } FinishedFaces++; } } // Generate a Vertex Buffer Object and store it with our vertices glGenBuffers(1, &m_VertexVBO); glBindBuffer(GL_ARRAY_BUFFER, m_VertexVBO); glBufferData(GL_ARRAY_BUFFER, sizeof(Lib3dsVector) * 3 * m_TotalFaces, vertices, GL_STATIC_DRAW); // Generate another Vertex Buffer Object and store the normals in it glGenBuffers(1, &m_NormalVBO); glBindBuffer(GL_ARRAY_BUFFER, m_NormalVBO); glBufferData(GL_ARRAY_BUFFER, sizeof(Lib3dsVector) * 3 * m_TotalFaces, normals, GL_STATIC_DRAW); // Generate a third VBO and store the texture coordinates in it. glGenBuffers(1, &m_TexCoordVBO); glBindBuffer(GL_ARRAY_BUFFER, m_TexCoordVBO); glBufferData(GL_ARRAY_BUFFER, sizeof(Lib3dsTexel) * 3 * m_TotalFaces, texCoords, GL_STATIC_DRAW); // Clean up our allocated memory delete vertices; delete normals; delete texCoords; // We no longer need lib3ds lib3ds_file_free(m_model); m_model = NULL; } void Object::applyTexture(const char*texfilename) { float imageWidth; float imageHeight; glGenTextures(1, & textureObject); // allocate memory for one texture textureObject = SOIL_load_OGL_texture(texfilename,SOIL_LOAD_AUTO,SOIL_CREATE_NEW_ID,SOIL_FLAG_MIPMAPS); glPixelStorei(GL_UNPACK_ALIGNMENT,1); glBindTexture(GL_TEXTURE_2D, textureObject); // use our newest texture glGetTexLevelParameterfv(GL_TEXTURE_2D,0,GL_TEXTURE_WIDTH,&imageWidth); glGetTexLevelParameterfv(GL_TEXTURE_2D,0,GL_TEXTURE_HEIGHT,&imageHeight); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); // give the best result for texture magnification glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); //give the best result for texture minification glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP); // don't repeat texture glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP); // don't repeat textureglTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP); // don't repeat texture glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE,GL_MODULATE); glTexImage2D(GL_TEXTURE_2D,0,GL_RGB,imageWidth,imageHeight,0,GL_RGB,GL_UNSIGNED_BYTE,& textureObject); } void Object::Draw() const { // Enable vertex, normal and texture-coordinate arrays. glEnableClientState(GL_VERTEX_ARRAY); glEnableClientState(GL_NORMAL_ARRAY); glEnableClientState(GL_TEXTURE_COORD_ARRAY); // Bind the VBO with the normals. glBindBuffer(GL_ARRAY_BUFFER, m_NormalVBO); // The pointer for the normals is NULL which means that OpenGL will use the currently bound VBO. glNormalPointer(GL_FLOAT, 0, NULL); glBindBuffer(GL_ARRAY_BUFFER, m_TexCoordVBO); glTexCoordPointer(2, GL_FLOAT, 0, NULL); glBindBuffer(GL_ARRAY_BUFFER, m_VertexVBO); glVertexPointer(3, GL_FLOAT, 0, NULL); // Render the triangles. glDrawArrays(GL_TRIANGLES, 0, m_TotalFaces * 3); glDisableClientState(GL_VERTEX_ARRAY); glDisableClientState(GL_NORMAL_ARRAY); glDisableClientState(GL_TEXTURE_COORD_ARRAY); } 3dsloader.h #include "main.h" #include "lib3ds/file.h" #include "lib3ds/mesh.h" #include "lib3ds/material.h" class Object { public: Object(std:: string filename); virtual ~Object(); virtual void Draw() const; virtual void CreateVBO(); void applyTexture(const char*texfilename); protected: void GetFaces(); unsigned int m_TotalFaces; Lib3dsFile * m_model; Lib3dsMesh* Mesh; GLuint textureObject; GLuint m_VertexVBO, m_NormalVBO, m_TexCoordVBO; }; Called in the main cpp file with: VBO,apply texture and draw (pretty simple, how ironic) and thats it, please help me forum :)

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  • Methods of learning / teaching programming

    - by Mark Avenius
    When I was in school, I had a difficult time getting into programming because of a catch-22 in the learning process: I didn't know how to write anything because I didn't know what keywords and commands meant. For example (as a student, I would think), "what does this using namespace std; thing do anyway? I didn't know what keywords and commands meant because I hadn't written anything. This basically led me to spending countless long night cursing the compiler as I made minor tweaks to my assignments until they would compile (and hopefully perform whatever operation they were supposed to). Is there a teaching/learning method that anyone uses that gets around this catch-22? I am trying to make this non-argumentative, which is why I don't want to know the 'best' method, but rather which methods exist.

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  • Efficient way to sort large set of numbers

    - by 7Aces
    I have to sort a set of 100000 integers as a part of a programming Q. The time limit is pretty restrictive, so I have to use the most time-efficient approach possible. My current code - #include<cstdio> #include<algorithm> using namespace std; int main() { int n,d[100000],i; for(i=0;i<n;++i) { scanf("%d",&d[i]); } sort(d,d+n); .... } Would this approach be more efiicient? int main() { int n,d[100000],i; for(i=0;i<n;++i) { scanf("%d",&d[i]); sort(d,d+i+1); } .... } What is the most efficient way to sort a large dataset? Note - Not homework...

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  • C#/.NET Little Wonders: The Generic Func Delegates

    - by James Michael Hare
    Once again, in this series of posts I look at the parts of the .NET Framework that may seem trivial, but can help improve your code by making it easier to write and maintain. The index of all my past little wonders posts can be found here. Back in one of my three original “Little Wonders” Trilogy of posts, I had listed generic delegates as one of the Little Wonders of .NET.  Later, someone posted a comment saying said that they would love more detail on the generic delegates and their uses, since my original entry just scratched the surface of them. Last week, I began our look at some of the handy generic delegates built into .NET with a description of delegates in general, and the Action family of delegates.  For this week, I’ll launch into a look at the Func family of generic delegates and how they can be used to support generic, reusable algorithms and classes. Quick Delegate Recap Delegates are similar to function pointers in C++ in that they allow you to store a reference to a method.  They can store references to either static or instance methods, and can actually be used to chain several methods together in one delegate. Delegates are very type-safe and can be satisfied with any standard method, anonymous method, or a lambda expression.  They can also be null as well (refers to no method), so care should be taken to make sure that the delegate is not null before you invoke it. Delegates are defined using the keyword delegate, where the delegate’s type name is placed where you would typically place the method name: 1: // This delegate matches any method that takes string, returns nothing 2: public delegate void Log(string message); This delegate defines a delegate type named Log that can be used to store references to any method(s) that satisfies its signature (whether instance, static, lambda expression, etc.). Delegate instances then can be assigned zero (null) or more methods using the operator = which replaces the existing delegate chain, or by using the operator += which adds a method to the end of a delegate chain: 1: // creates a delegate instance named currentLogger defaulted to Console.WriteLine (static method) 2: Log currentLogger = Console.Out.WriteLine; 3:  4: // invokes the delegate, which writes to the console out 5: currentLogger("Hi Standard Out!"); 6:  7: // append a delegate to Console.Error.WriteLine to go to std error 8: currentLogger += Console.Error.WriteLine; 9:  10: // invokes the delegate chain and writes message to std out and std err 11: currentLogger("Hi Standard Out and Error!"); While delegates give us a lot of power, it can be cumbersome to re-create fairly standard delegate definitions repeatedly, for this purpose the generic delegates were introduced in various stages in .NET.  These support various method types with particular signatures. Note: a caveat with generic delegates is that while they can support multiple parameters, they do not match methods that contains ref or out parameters. If you want to a delegate to represent methods that takes ref or out parameters, you will need to create a custom delegate. We’ve got the Func… delegates Just like it’s cousin, the Action delegate family, the Func delegate family gives us a lot of power to use generic delegates to make classes and algorithms more generic.  Using them keeps us from having to define a new delegate type when need to make a class or algorithm generic. Remember that the point of the Action delegate family was to be able to perform an “action” on an item, with no return results.  Thus Action delegates can be used to represent most methods that take 0 to 16 arguments but return void.  You can assign a method The Func delegate family was introduced in .NET 3.5 with the advent of LINQ, and gives us the power to define a function that can be called on 0 to 16 arguments and returns a result.  Thus, the main difference between Action and Func, from a delegate perspective, is that Actions return nothing, but Funcs return a result. The Func family of delegates have signatures as follows: Func<TResult> – matches a method that takes no arguments, and returns value of type TResult. Func<T, TResult> – matches a method that takes an argument of type T, and returns value of type TResult. Func<T1, T2, TResult> – matches a method that takes arguments of type T1 and T2, and returns value of type TResult. Func<T1, T2, …, TResult> – and so on up to 16 arguments, and returns value of type TResult. These are handy because they quickly allow you to be able to specify that a method or class you design will perform a function to produce a result as long as the method you specify meets the signature. For example, let’s say you were designing a generic aggregator, and you wanted to allow the user to define how the values will be aggregated into the result (i.e. Sum, Min, Max, etc…).  To do this, we would ask the user of our class to pass in a method that would take the current total, the next value, and produce a new total.  A class like this could look like: 1: public sealed class Aggregator<TValue, TResult> 2: { 3: // holds method that takes previous result, combines with next value, creates new result 4: private Func<TResult, TValue, TResult> _aggregationMethod; 5:  6: // gets or sets the current result of aggregation 7: public TResult Result { get; private set; } 8:  9: // construct the aggregator given the method to use to aggregate values 10: public Aggregator(Func<TResult, TValue, TResult> aggregationMethod = null) 11: { 12: if (aggregationMethod == null) throw new ArgumentNullException("aggregationMethod"); 13:  14: _aggregationMethod = aggregationMethod; 15: } 16:  17: // method to add next value 18: public void Aggregate(TValue nextValue) 19: { 20: // performs the aggregation method function on the current result and next and sets to current result 21: Result = _aggregationMethod(Result, nextValue); 22: } 23: } Of course, LINQ already has an Aggregate extension method, but that works on a sequence of IEnumerable<T>, whereas this is designed to work more with aggregating single results over time (such as keeping track of a max response time for a service). We could then use this generic aggregator to find the sum of a series of values over time, or the max of a series of values over time (among other things): 1: // creates an aggregator that adds the next to the total to sum the values 2: var sumAggregator = new Aggregator<int, int>((total, next) => total + next); 3:  4: // creates an aggregator (using static method) that returns the max of previous result and next 5: var maxAggregator = new Aggregator<int, int>(Math.Max); So, if we were timing the response time of a web method every time it was called, we could pass that response time to both of these aggregators to get an idea of the total time spent in that web method, and the max time spent in any one call to the web method: 1: // total will be 13 and max 13 2: int responseTime = 13; 3: sumAggregator.Aggregate(responseTime); 4: maxAggregator.Aggregate(responseTime); 5:  6: // total will be 20 and max still 13 7: responseTime = 7; 8: sumAggregator.Aggregate(responseTime); 9: maxAggregator.Aggregate(responseTime); 10:  11: // total will be 40 and max now 20 12: responseTime = 20; 13: sumAggregator.Aggregate(responseTime); 14: maxAggregator.Aggregate(responseTime); The Func delegate family is useful for making generic algorithms and classes, and in particular allows the caller of the method or user of the class to specify a function to be performed in order to generate a result. What is the result of a Func delegate chain? If you remember, we said earlier that you can assign multiple methods to a delegate by using the += operator to chain them.  So how does this affect delegates such as Func that return a value, when applied to something like the code below? 1: Func<int, int, int> combo = null; 2:  3: // What if we wanted to aggregate the sum and max together? 4: combo += (total, next) => total + next; 5: combo += Math.Max; 6:  7: // what is the result? 8: var comboAggregator = new Aggregator<int, int>(combo); Well, in .NET if you chain multiple methods in a delegate, they will all get invoked, but the result of the delegate is the result of the last method invoked in the chain.  Thus, this aggregator would always result in the Math.Max() result.  The other chained method (the sum) gets executed first, but it’s result is thrown away: 1: // result is 13 2: int responseTime = 13; 3: comboAggregator.Aggregate(responseTime); 4:  5: // result is still 13 6: responseTime = 7; 7: comboAggregator.Aggregate(responseTime); 8:  9: // result is now 20 10: responseTime = 20; 11: comboAggregator.Aggregate(responseTime); So remember, you can chain multiple Func (or other delegates that return values) together, but if you do so you will only get the last executed result. Func delegates and co-variance/contra-variance in .NET 4.0 Just like the Action delegate, as of .NET 4.0, the Func delegate family is contra-variant on its arguments.  In addition, it is co-variant on its return type.  To support this, in .NET 4.0 the signatures of the Func delegates changed to: Func<out TResult> – matches a method that takes no arguments, and returns value of type TResult (or a more derived type). Func<in T, out TResult> – matches a method that takes an argument of type T (or a less derived type), and returns value of type TResult(or a more derived type). Func<in T1, in T2, out TResult> – matches a method that takes arguments of type T1 and T2 (or less derived types), and returns value of type TResult (or a more derived type). Func<in T1, in T2, …, out TResult> – and so on up to 16 arguments, and returns value of type TResult (or a more derived type). Notice the addition of the in and out keywords before each of the generic type placeholders.  As we saw last week, the in keyword is used to specify that a generic type can be contra-variant -- it can match the given type or a type that is less derived.  However, the out keyword, is used to specify that a generic type can be co-variant -- it can match the given type or a type that is more derived. On contra-variance, if you are saying you need an function that will accept a string, you can just as easily give it an function that accepts an object.  In other words, if you say “give me an function that will process dogs”, I could pass you a method that will process any animal, because all dogs are animals.  On the co-variance side, if you are saying you need a function that returns an object, you can just as easily pass it a function that returns a string because any string returned from the given method can be accepted by a delegate expecting an object result, since string is more derived.  Once again, in other words, if you say “give me a method that creates an animal”, I can pass you a method that will create a dog, because all dogs are animals. It really all makes sense, you can pass a more specific thing to a less specific parameter, and you can return a more specific thing as a less specific result.  In other words, pay attention to the direction the item travels (parameters go in, results come out).  Keeping that in mind, you can always pass more specific things in and return more specific things out. For example, in the code below, we have a method that takes a Func<object> to generate an object, but we can pass it a Func<string> because the return type of object can obviously accept a return value of string as well: 1: // since Func<object> is co-variant, this will access Func<string>, etc... 2: public static string Sequence(int count, Func<object> generator) 3: { 4: var builder = new StringBuilder(); 5:  6: for (int i=0; i<count; i++) 7: { 8: object value = generator(); 9: builder.Append(value); 10: } 11:  12: return builder.ToString(); 13: } Even though the method above takes a Func<object>, we can pass a Func<string> because the TResult type placeholder is co-variant and accepts types that are more derived as well: 1: // delegate that's typed to return string. 2: Func<string> stringGenerator = () => DateTime.Now.ToString(); 3:  4: // This will work in .NET 4.0, but not in previous versions 5: Sequence(100, stringGenerator); Previous versions of .NET implemented some forms of co-variance and contra-variance before, but .NET 4.0 goes one step further and allows you to pass or assign an Func<A, BResult> to a Func<Y, ZResult> as long as A is less derived (or same) as Y, and BResult is more derived (or same) as ZResult. Sidebar: The Func and the Predicate A method that takes one argument and returns a bool is generally thought of as a predicate.  Predicates are used to examine an item and determine whether that item satisfies a particular condition.  Predicates are typically unary, but you may also have binary and other predicates as well. Predicates are often used to filter results, such as in the LINQ Where() extension method: 1: var numbers = new[] { 1, 2, 4, 13, 8, 10, 27 }; 2:  3: // call Where() using a predicate which determines if the number is even 4: var evens = numbers.Where(num => num % 2 == 0); As of .NET 3.5, predicates are typically represented as Func<T, bool> where T is the type of the item to examine.  Previous to .NET 3.5, there was a Predicate<T> type that tended to be used (which we’ll discuss next week) and is still supported, but most developers recommend using Func<T, bool> now, as it prevents confusion with overloads that accept unary predicates and binary predicates, etc.: 1: // this seems more confusing as an overload set, because of Predicate vs Func 2: public static SomeMethod(Predicate<int> unaryPredicate) { } 3: public static SomeMethod(Func<int, int, bool> binaryPredicate) { } 4:  5: // this seems more consistent as an overload set, since just uses Func 6: public static SomeMethod(Func<int, bool> unaryPredicate) { } 7: public static SomeMethod(Func<int, int, bool> binaryPredicate) { } Also, even though Predicate<T> and Func<T, bool> match the same signatures, they are separate types!  Thus you cannot assign a Predicate<T> instance to a Func<T, bool> instance and vice versa: 1: // the same method, lambda expression, etc can be assigned to both 2: Predicate<int> isEven = i => (i % 2) == 0; 3: Func<int, bool> alsoIsEven = i => (i % 2) == 0; 4:  5: // but the delegate instances cannot be directly assigned, strongly typed! 6: // ERROR: cannot convert type... 7: isEven = alsoIsEven; 8:  9: // however, you can assign by wrapping in a new instance: 10: isEven = new Predicate<int>(alsoIsEven); 11: alsoIsEven = new Func<int, bool>(isEven); So, the general advice that seems to come from most developers is that Predicate<T> is still supported, but we should use Func<T, bool> for consistency in .NET 3.5 and above. Sidebar: Func as a Generator for Unit Testing One area of difficulty in unit testing can be unit testing code that is based on time of day.  We’d still want to unit test our code to make sure the logic is accurate, but we don’t want the results of our unit tests to be dependent on the time they are run. One way (of many) around this is to create an internal generator that will produce the “current” time of day.  This would default to returning result from DateTime.Now (or some other method), but we could inject specific times for our unit testing.  Generators are typically methods that return (generate) a value for use in a class/method. For example, say we are creating a CacheItem<T> class that represents an item in the cache, and we want to make sure the item shows as expired if the age is more than 30 seconds.  Such a class could look like: 1: // responsible for maintaining an item of type T in the cache 2: public sealed class CacheItem<T> 3: { 4: // helper method that returns the current time 5: private static Func<DateTime> _timeGenerator = () => DateTime.Now; 6:  7: // allows internal access to the time generator 8: internal static Func<DateTime> TimeGenerator 9: { 10: get { return _timeGenerator; } 11: set { _timeGenerator = value; } 12: } 13:  14: // time the item was cached 15: public DateTime CachedTime { get; private set; } 16:  17: // the item cached 18: public T Value { get; private set; } 19:  20: // item is expired if older than 30 seconds 21: public bool IsExpired 22: { 23: get { return _timeGenerator() - CachedTime > TimeSpan.FromSeconds(30.0); } 24: } 25:  26: // creates the new cached item, setting cached time to "current" time 27: public CacheItem(T value) 28: { 29: Value = value; 30: CachedTime = _timeGenerator(); 31: } 32: } Then, we can use this construct to unit test our CacheItem<T> without any time dependencies: 1: var baseTime = DateTime.Now; 2:  3: // start with current time stored above (so doesn't drift) 4: CacheItem<int>.TimeGenerator = () => baseTime; 5:  6: var target = new CacheItem<int>(13); 7:  8: // now add 15 seconds, should still be non-expired 9: CacheItem<int>.TimeGenerator = () => baseTime.AddSeconds(15); 10:  11: Assert.IsFalse(target.IsExpired); 12:  13: // now add 31 seconds, should now be expired 14: CacheItem<int>.TimeGenerator = () => baseTime.AddSeconds(31); 15:  16: Assert.IsTrue(target.IsExpired); Now we can unit test for 1 second before, 1 second after, 1 millisecond before, 1 day after, etc.  Func delegates can be a handy tool for this type of value generation to support more testable code.  Summary Generic delegates give us a lot of power to make truly generic algorithms and classes.  The Func family of delegates is a great way to be able to specify functions to calculate a result based on 0-16 arguments.  Stay tuned in the weeks that follow for other generic delegates in the .NET Framework!   Tweet Technorati Tags: .NET, C#, CSharp, Little Wonders, Generics, Func, Delegates

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  • Game Timer In C++

    - by user1870398
    I need to be able to find out how many milliseconds since that last update. Is there any way I can find it out with time rather then a thread that counts like I did below? #include <iostream> #include<windows.h> #include<time.h> #include<process.h> using namespace std; int Timer = 0; int LastTimer = 0; bool End = false; void Update(int Ticks) { } void UpdateTimer() { while (true) { LastTimer = Timer; Timer++; Sleep(1); if (End) break; } } int WINAPI WinMain(HINSTANCE par1, HINSTANCE par2, LPSTR par3, int par4) { _beginthread(UpdateTimer, 0, NULL); while(true) { if (Timer == 1000) Timer = 0; Update(Timer - LastTimer); } }

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  • Why doesn't the Visual Studio C compiler like this? [migrated]

    - by justin
    The following code compiles fine on Linux using gcc -std=c99 but gets the following errors on the Visual Studio 2010 C compiler: Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 16.00.40219.01 for 80x86 Copyright (C) Microsoft Corporation. All rights reserved. fib.c fib.c(42) : error C2057: expected constant expression fib.c(42) : error C2466: cannot allocate an array of constant size 0 fib.c(42) : error C2133: 'num' : unknown size The user inputs the amount of Fibonacci numbers to generate. I'm curious as to why the Microsoft compiler doesn't like this code. http://pastebin.com/z0uEa2zw

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  • How can I read kindle book under xfce(ubuntu)? (using chromebook)(wine not working)

    - by yshn
    I'm using chromebook, dual booting xfce(ubuntu) and cr os. The ebook I bought on amazon is not supported on kindle cloud reader. (Under xfce)I downloaded wine and tried installing kindle for pc under wine, and after couples of times of trials, it always said installation error and could not install kindle, and it's been giving me: Unhandled exception: unimplemented function msvcp90.dll.??0?$basic_ofstream@DU?$char_traits@D@std@@@std@@QAE@XZ called in 32-bit code (0x7b839cf2). Register dump: CS:0023 SS:002b DS:002b ES:002b FS:0063 GS:006b EIP:7b839cf2 ESP:0033fcd4 EBP:0033fd38 EFLAGS:00000287( - -- I S - -P-C) EAX:7b826245 EBX:7b894ff4 ECX:00000008 EDX:0033fcf4 ESI:80000100 EDI:00dca568 Stack dump: 0x0033fcd4: 0033fd58 00000008 00000030 80000100 0x0033fce4: 00000001 00000000 7b839cf2 00000002 0x0033fcf4: 7e24b340 7e24f2ca 0000000d 00110000 0x0033fd04: 7bc47a0d 7e1dbff4 7e1417f0 00dca568 0x0033fd14: 0033fd24 7bc65d0b 00110000 00000000 0x0033fd24: 0033fd44 7e141801 7b839caa 7e1dbff4 000c: sel=0067 base=00000000 limit=00000000 16-bit r-x Backtrace: =0 0x7b839cf2 in kernel32 (+0x29cf2) (0x0033fd38) 1 0x7e24b2a8 in msvcp90 (+0x3b2a7) (0x0033fd68) 2 0x7e216c9d in msvcp90 (+0x6c9c) (0x0033fde8) 3 0x00938fdd in kindle (+0x538fdc) (0x0033fde8) 4 0x0089dc71 in kindle (+0x49dc70) (0x0033fe70) 5 0x7b859cdc call_process_entry+0xb() in kernel32 (0x0033fe88) 6 0x7b85af4f in kernel32 (+0x4af4e) (0x0033fec8) 7 0x7bc71db0 call_thread_func_wrapper+0xb() in ntdll (0x0033fed8) 8 0x7bc7486d call_thread_func+0x7c() in ntdll (0x0033ffa8) 9 0x7bc71d8e RtlRaiseException+0x21() in ntdll (0x0033ffc8) 10 0x7bc49f4e call_dll_entry_point+0x61d() in ntdll (0x0033ffe8) 0x7b839cf2: subl $4,%esp Modules: Module Address Debug info Name (130 modules) PE 340000- 37d000 Deferred ssleay32 PE 390000- 3ca000 Deferred webcoreviewer PE 3d0000- 3e0000 Deferred pthreadvc2 PE 400000- 1433000 Export kindle PE 1440000- 155c000 Deferred libeay32 PE 1560000- 169f000 Deferred qtscript4 PE 16a0000- 1795000 Deferred libxml2 PE 17a0000- 18c7000 Deferred javascriptcore PE 18d0000- 1974000 Deferred cflite PE 1980000- 2048000 Deferred libwebcore PE 2050000- 208d000 Deferred libjpeg PE 10000000-10a34000 Deferred qtwebkit4 PE 4a800000-4a8eb000 Deferred icuuc46 PE 4a900000-4aa36000 Deferred icuin46 PE 4ad00000-4bb80000 Deferred icudt46 PE 5a4c0000-5a4d4000 Deferred zlib1 PE 61000000-61056000 Deferred qtxml4 PE 62000000-62093000 Deferred qtsql4 PE 64000000-640ef000 Deferred qtnetwork4 PE 65000000-657b8000 Deferred qtgui4 PE 67000000-67228000 Deferred qtcore4 PE 78050000-780b9000 Deferred msvcp100 PE 78aa0000-78b5e000 Deferred msvcr100 ELF 7b800000-7ba15000 Dwarf kernel32 -PE 7b810000-7ba15000 \ kernel32 ELF 7bc00000-7bcc3000 Dwarf ntdll -PE 7bc10000-7bcc3000 \ ntdll ELF 7bf00000-7bf04000 Deferred ELF 7d7f7000-7d800000 Deferred librt.so.1 ELF 7d800000-7d818000 Deferred libresolv.so.2 ELF 7d818000-7d861000 Deferred libdbus-1.so.3 ELF 7d861000-7d873000 Deferred libp11-kit.so.0 ELF 7d873000-7d8f8000 Deferred libgcrypt.so.11 ELF 7d8f8000-7d90a000 Deferred libtasn1.so.3 ELF 7d90a000-7d913000 Deferred libkrb5support.so.0 ELF 7d913000-7d9e2000 Deferred libkrb5.so.3 ELF 7da42000-7da47000 Deferred libgpg-error.so.0 ELF 7da47000-7da6f000 Deferred libk5crypto.so.3 ELF 7da6f000-7da81000 Deferred libavahi-client.so.3 ELF 7da81000-7da8f000 Deferred libavahi-common.so.3 ELF 7da8f000-7db53000 Deferred libgnutls.so.26 ELF 7db53000-7db91000 Deferred libgssapi_krb5.so.2 ELF 7db91000-7dbe4000 Deferred libcups.so.2 ELF 7dc21000-7dc55000 Deferred uxtheme -PE 7dc30000-7dc55000 \ uxtheme ELF 7dc55000-7dc5b000 Deferred libxfixes.so.3 ELF 7dc5b000-7dc66000 Deferred libxcursor.so.1 ELF 7dc6a000-7dc6e000 Deferred libkeyutils.so.1 ELF 7dc6e000-7dc73000 Deferred libcom_err.so.2 ELF 7dca5000-7dccf000 Deferred libexpat.so.1 ELF 7dccf000-7dd03000 Deferred libfontconfig.so.1 ELF 7dd03000-7dd13000 Deferred libxi.so.6 ELF 7dd13000-7dd17000 Deferred libxcomposite.so.1 ELF 7dd17000-7dd20000 Deferred libxrandr.so.2 ELF 7dd20000-7dd2a000 Deferred libxrender.so.1 ELF 7dd2a000-7dd30000 Deferred libxxf86vm.so.1 ELF 7dd30000-7dd34000 Deferred libxinerama.so.1 ELF 7dd34000-7dd3b000 Deferred libxdmcp.so.6 ELF 7dd3b000-7dd5c000 Deferred libxcb.so.1 ELF 7dd5c000-7dd76000 Deferred libice.so.6 ELF 7dd76000-7deaa000 Deferred libx11.so.6 ELF 7deaa000-7debc000 Deferred libxext.so.6 ELF 7debc000-7dec5000 Deferred libsm.so.6 ELF 7ded4000-7df67000 Deferred winex11 -PE 7dee0000-7df67000 \ winex11 ELF 7df67000-7e001000 Deferred libfreetype.so.6 ELF 7e001000-7e023000 Deferred iphlpapi -PE 7e010000-7e023000 \ iphlpapi ELF 7e023000-7e03e000 Deferred wsock32 -PE 7e030000-7e03e000 \ wsock32 ELF 7e03e000-7e071000 Deferred wintrust -PE 7e040000-7e071000 \ wintrust ELF 7e071000-7e129000 Deferred crypt32 -PE 7e080000-7e129000 \ crypt32 ELF 7e129000-7e158000 Deferred msvcr90 -PE 7e130000-7e158000 \ msvcr90 ELF 7e158000-7e1e5000 Deferred msvcrt -PE 7e170000-7e1e5000 \ msvcrt ELF 7e1e5000-7e2ca000 Dwarf msvcp90 -PE 7e210000-7e2ca000 \ msvcp90 ELF 7e2ca000-7e2ec000 Deferred imm32 -PE 7e2d0000-7e2ec000 \ imm32 ELF 7e2ec000-7e3de000 Deferred oleaut32 -PE 7e300000-7e3de000 \ oleaut32 ELF 7e3de000-7e418000 Deferred winspool -PE 7e3f0000-7e418000 \ winspool ELF 7e418000-7e4f7000 Deferred comdlg32 -PE 7e420000-7e4f7000 \ comdlg32 ELF 7e4f7000-7e51f000 Deferred msacm32 -PE 7e500000-7e51f000 \ msacm32 ELF 7e51f000-7e5cc000 Deferred winmm -PE 7e530000-7e5cc000 \ winmm ELF 7e5cc000-7e641000 Deferred rpcrt4 -PE 7e5e0000-7e641000 \ rpcrt4 ELF 7e641000-7e749000 Deferred ole32 -PE 7e660000-7e749000 \ ole32 ELF 7e749000-7e841000 Deferred comctl32 -PE 7e750000-7e841000 \ comctl32 ELF 7e841000-7ea52000 Deferred shell32 -PE 7e850000-7ea52000 \ shell32 ELF 7ea52000-7eabc000 Deferred shlwapi -PE 7ea60000-7eabc000 \ shlwapi ELF 7eabc000-7ead5000 Deferred version -PE 7eac0000-7ead5000 \ version ELF 7ead5000-7eb35000 Deferred advapi32 -PE 7eae0000-7eb35000 \ advapi32 ELF 7eb35000-7ebf2000 Deferred gdi32 -PE 7eb40000-7ebf2000 \ gdi32 ELF 7ebf2000-7ed32000 Deferred user32 -PE 7ec00000-7ed32000 \ user32 ELF 7ed32000-7ed58000 Deferred mpr -PE 7ed40000-7ed58000 \ mpr ELF 7ed58000-7ed6e000 Deferred libz.so.1 ELF 7ed6e000-7eddd000 Deferred wininet -PE 7ed80000-7eddd000 \ wininet ELF 7eddd000-7ee0f000 Deferred ws2_32 -PE 7ede0000-7ee0f000 \ ws2_32 ELF 7ee0f000-7ee1c000 Deferred libnss_files.so.2 ELF 7ee1c000-7ee28000 Deferred libnss_nis.so.2 ELF 7ee28000-7ee42000 Deferred libnsl.so.1 ELF 7ee42000-7ee4b000 Deferred libnss_compat.so.2 ELF 7efd4000-7f000000 Deferred libm.so.6 ELF f74a3000-f74a7000 Deferred libxau.so.6 ELF f74a8000-f74ad000 Deferred libdl.so.2 ELF f74ad000-f7657000 Deferred libc.so.6 ELF f7658000-f7673000 Deferred libpthread.so.0 ELF f7675000-f767b000 Deferred libuuid.so.1 ELF f7682000-f77c4000 Dwarf libwine.so.1 ELF f77c6000-f77e8000 Deferred ld-linux.so.2 ELF f77e8000-f77e9000 Deferred [vdso].so Threads: process tid prio (all id:s are in hex) 0000000e services.exe 0000001f 0 0000001e 0 00000015 0 00000010 0 0000000f 0 00000012 winedevice.exe 0000001c 0 00000019 0 00000014 0 00000013 0 0000001a plugplay.exe 00000020 0 0000001d 0 0000001b 0 00000037 explorer.exe 00000038 0 00000042 (D) C:\Program Files (x86)\Amazon\Kindle\Kindle.exe 00000043 0 <== System information: Wine build: wine-1.4 Platform: i386 (WOW64) Host system: Linux Host version: 3.8.11 How can this be fixed?

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  • How do you name your personal libraries?

    - by Mehrdad
    I'm pretty bad with naming things. The only name I can every generically come up with is 'helper'. Say, if I have a header file that contains helping functions for manipulating paths, I tend to put it inside my "helper" directory and call it "path-helper.hpp" or something like that. Obviouslly, that's a bad naming convention. :) I want to have a consistent naming scheme for my folder (and namespace) which I can use to always refer to my own headers and libraries, but I have trouble finding names that are easy to type or remember (like boost)... so I end up calling some of them "helper" or "stdext" or whatnot, which isn't a great idea. How do you find names for your libraries that are easy to remember and easy to type, and which aren't too generic (like "helper" or "std" or "stdext" or the like)? Any suggestions on how to go about doing this?

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  • Drawing Flowchart for function calculate a number in the Fibonacci Series

    - by truongvan
    I'm trying make Flowchart for function calculate a number in the Fibonacci Series. But It looks like not right. I don't how draw the recursive function. Please help me how to fix it. My flowchart: DIA This is my code: #include <iostream> using namespace std; long long Fibonacci(int input); int main() { cout << "Input Fibonacci Index number: "; int Index = 0; cin >> Index; cout << Fibonacci(i) << endl; return 0; } long long Fibonacci(int input) { if (input < 2) return input; else { return Fibonacci(input - 1) + Fibonacci(input - 2); } }

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  • How to efficiently map tokens to code in a script interpreter?

    - by lithander
    I'm writing an interpreter for a simple scripting language where each line is a complete, executable command. (Like the instructions in assembler) When parsing a line I have to map the requested command to actual code. My current solution looks like this: std::string op, param1, param2; //parse line, identify op, param1, param2 ... //call command specific code if(op == "MOV") ExecuteMov(AsNumber(param1)); else if(op == "ROT") ExecuteRot(AsNumber(param1)); else if(op == "SZE") ExecuteSze(AsNumber(param1)); else if(op == "POS") ExecutePos((AsNumber(param1), AsNumber(param2)); else if(op == "DIR") ExecuteDir((AsNumber(param1), AsNumber(param2)); else if(op == "SET") ExecuteSet(param1, AsNumber(param2)); else if(op == "EVL") ... The more commands are supported the more string comparisions I'll have to do to identify and call the associated method. Can you point me to a more efficient implementation in the described scenario?

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  • Why is bzip2 needed in the kernel patch instructions?

    - by user12657
    This was from here. Extract the patch tar -xvzf /usr/src/web100-2.5.22-200810130047.tar.gz bzip2 web100/ web100-2.6.27-2.5.22-200810130047.patch Test the patch bzip2 -dc /usr/src/linux/web100/ web100-2.6.27-2.5.22-200810130047.patch.bz2 | patch -p1 --dry-run I looked at the .patch, the diff output of many files and the file .patch.bz2 after the bzip2 command which is too also the diff output of many files, they seem to be the same. My question is why is bzip2 even needed to turn the .patch into a .patch.bz2? Is it for the redirection to std output from the -dc option for the patch command? Even if it is, why not just not just use the patch command in the form something like this:patch -p1 < patchfile? I don't see why the bzip2 is done here. Also, I think the bzip2 might have an extra space in the command after web100/, right?

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  • Material, Pass, Technique and shaders

    - by Papi75
    I'm trying to make a clean and advanced Material class for the rendering of my game, here is my architecture: class Material { void sendToShader() { program->sendUniform( nameInShader, valueInMaterialOrOther ); } private: Blend blendmode; ///< Alpha, Add, Multiply, … Color ambient; Color diffuse; Color specular; DrawingMode drawingMode; // Line Triangles, … Program* program; std::map<string, TexturePacket> textures; // List of textures with TexturePacket = { Texture*, vec2 offset, vec2 scale} }; How can I handle the link between the Shader and the Material? (sendToShader method) If the user want to send additionals informations to the shader (like time elapsed), how can I allow that? (User can't edit Material class) Thanks!

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  • How to modify grub entry for supporting KGDB kernel image?

    - by Nishant
    I am trying to update target m/c grub.cfg file for KGDB setup but while booting the m/c it got hung completely and not asking/waiting for remote gdb connection. Following is the entry which I added:- menuentry 'Ubuntu, with Linux 2.6.32-24-kgdb' --class ubuntu --class gnu-linux --class gnu --class os { recordfail insmod ext2 set root='(hd0,1)' search --no-floppy --fs-uuid --set 12878c3b-c553-4b4b-986a-6e32daea3ad1 linux /vmlinuz-2.6.32-kgdb root=/dev/mapper/ubuntu-root ro kgdbwait [email protected]/,@192.168.140.158/ quiet initrd /initrd.img-2.6.32-24-server } I have also compiled and copied /boot/vmlinuz-2.6.15.5-kgdb & /boot/System.map-2.6.15.5-kgdb to target m/c from devlopement m/c. STD entry before adding KGDB in grub.cfg was:- menuentry 'Ubuntu, with Linux 2.6.32-24-server' --class ubuntu --class gnu-linux --class gnu --class os { recordfail insmod ext2 set root='(hd0,1)' search --no-floppy --fs-uuid --set 12878c3b-c553-4b4b-986a-6e32daea3ad1 linux /vmlinuz-2.6.32-24-server root=/dev/mapper/ubuntu-root ro quiet initrd /initrd.img-2.6.32-24-server } Please suggest how to get rid of this problem.

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  • design for a parser to handle very large files

    - by user619818
    I have written a program which records protocol messages between an application and a hardware device which matches each application request with each hardware response. This is so that I can later remove the hardware, connect a 'replay' application to the main application and wait for an application request and reply with a matched copy of the requisite hardware reply message. My replay application saves the matched request/response in a list (using C++ std::list). This works fine on a small interaction session. My problem now is that I need to be able to use the replay over a long long session. With my current implementation, the replay program eventually uses up all available memory on my computer and crashes. So I need some sort of lookahead - and not parse the whole session in one go. Can anyone make any suggestions on how to get started?

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  • Motivation Problems, Middle School Programmer [closed]

    - by Anonymous
    I'm in middle school at the moment and have been programming for about a year and a half. I mostly work with Python and Ruby, and am currently learning Rails. I know, you can never learn enough, it takes a looong time to master a subject, but I feel like I don't have much left to learn :(. I've learned many concepts in Python, learned basically the whole std lib and have written a ton of programs, same with Ruby. In Ruby I've also done a lot of metaprogramming. After I've learned all the concepts, and written a lot of programs, there is nothing really left for me to do! What can I do, now that I've learned all the concepts, and written some programs? I can't get a job working with real developers, and the programming camp I went to last year was far too easy.

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  • How to make the switch to C++11?

    - by Overv
    I've been programming in C++ for a while now, but mostly thinks centered around the low-level features of C++. By that I mean mostly working with pointers and raw arrays. I think this behavior is known as using C++ as C with classes despite me only having tried C recently for the first time. I was pleasantly surprised how languages like C# and Java hide these details away in convenient standard library classes like Dictionaries and Lists. I'm aware that the C++ standard library has many convenience containers like vectors, maps and strings as well and C++11 only adds to this by having std:: array and ranged loops. How do I best learn to make use of these modern language features and which are suitable for which moments? Is it correct that software engineering in C++ nowadays I'd mostly free of manual memory management? Lastly, which compiler should I use to make the most of the new standard? Visual Studio has excellent debugging tools, but even VS2012 seems to have terrible C++11 support.

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  • Deleting a game object causing an access violation

    - by Balls
    I tried doing this but it cause an access violation. void GameObjectFactory::Update() { for( std::list<GameObject*>::iterator it=gameObjectList.begin() ..... (*it)->Update(); } void Bomb::Update() { if( time == 2.0f ) { gameObjectFactory->Remove( this ); } } void GameObjectFactory::Remove( ... ) { gameObjectList.remove( ... ); } My thoughts would be to mark the object to be dead then let the factory handle it the on next frame for deletion. Is it the best and fastest way? What do you think?

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  • De-facto standards for customer information record

    - by maasg
    I'm currently evaluating a potential new project that involves creating a DB for typical customer information (userid, pwd, first & last name, email, adress, telfnr ...). At this point, requirements are only roughly defined. The customer DB is expected in the O(millions) of records. In order to calculate some back-of-the-envelope numbers for DB sizing and evaluate potential DB options & architectures, I'm looking for some de-facto standards for these kind of records. In particular, the std size of every field (first name, last name, address,...) or typical avg for a simple customer record would be great info. With so many e-commerce websites out there, there should be some kind of typical config that can be reused and avoid re-inventing the wheel. Any ideas?

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  • What is a right datatype in C++ for OpenGL scene representation with use of GLSL

    - by Rarach
    I am programming in C++ OpenGl with GLSL. Until now I have been using a data structure that is composed of std::vector filled with structures of vertexes and with their parameters (position , normal, color ...) as a global variable for all the code. My question is, as I am using VBOs for drawing - is this a good approach to this problem? I am asking because I happen to have a lot of memory related trouble with this structure. I am trying to generate a terrain with a lot of vertices - more than 1 million. This seems to work, but as I refill the buffer I get memory related issues (crushes that occur, more or less randomly). So again the question is, is this a good data structure to use / and look for the faults in my code, or should I change to something else? Or what data structure would be advisable?

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  • Programming Interview : How to debug a program?

    - by Jake
    I was recently asked the following question in an interview : How do you debug a C++ program ? I started by explaining that programs may have syntax and semantic errors. Compiler reports the syntax errors which can be corrected. For semantic errors, various debuggers are available. I specifically talked about gdb, which is command line, and Visual Studio IDE's debugger, which has a GUI, and common commands. I also talked about debug and release version of code, how assertions should be used for debug build, how exceptions helps in automatic cleanup & putting the program in valid state, and how logging can be useful (e.g. using std::clog). I want to know if this answer is complete or not. Also, I want to hear how other people will go about answering this question in a structured manner ? Thanks.

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  • are there compiler options in clang? [on hold]

    - by Deohboeh
    I am learning from The C++ Primer. One of the exercises is to compile a program with arguments in main(). For this I am trying to use mac terminal. I need to compile a C++11 Unix executable file named "main" which takes “f" as an argument. I am using Xcode 4.6.3 on OS X Lion. I compiled the program with clang++ -std=c++11 -stdlib=libc++ main.cpp -o main. But don’t know what to do next. I found -frecord-gcc-switches while searching compiler options on google. It does what I need to do. Is there a clang version of this? Please use simple language. I have never used command line before. I tried going through the clang user guide but a lot of it is out of my depth.

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  • No such file but the file is there!

    - by user288757
    I'm trying to compile a C++ file with some includes. My main file (well I didn't make it hdf5_getters includes a file which includes the file hdf5.h, also not my design but it's a downloaded library. Every time I try to compile it I get the error message that the file hdf5.h does not exist while it clearly does. I started reading on the internet and people say it can happen because it's a 32bit binary running on a 64bit architecture. But I'm running a 32bit Ubuntu so that can't be it... I'm out of ideas, if anyone can help me please :) This is the errormessage with commands: make hdf5_getters g++ -c -Wall -std=c++0x -O2 -c hdf5_getters.cc In file included from H5Cpp.h:20:0, from hdf5_getters.cc:34: H5Include.h:17:18: fatal error: hdf5.h: No such file or directory #include <hdf5.h> ^ compilation terminated. make: *** [hdf5_getters.o] Error 1

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  • Is this a valid HTTP response? [migrated]

    - by fatmck
    I am writing a web server using C++, which responds the following for all requests: static std::string rsp[] = { "HTTP/1.1 200 OK\r\n", "Server: WebServer\r\n", "Content-Type: text/html\r\n", "Content-Length: 3\r\n", "Connection: close\r\n", "\r\n", "123" }; the content "123" can be successfully shown in browser. But when I use apache-ab to do a test, ab always show errors like this: ab -n 1 -c 1 http://127.0.0.1:1080/ apr_socket_recv: Connection reset by peer (104) I thought that I'm closing the socket too quickly, so I commented the close() function. But ab just hold, ab seems to be waiting for a complete response.

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