const - Page 11 - Developer IT

How to define type member constant in F# ?

- by zproxy

In C# one can define a type member constant like this: class Foo { public const int Bar = 600; } The IL shall looks like this. .field public static literal int32 Bar = int32(600) How can I do the same within Visual F# / FSharp? I tried this to no avail: [<Sealed>] type Foo() = [<Literal>] let Bar = 600

Read the article

gcc compiler error in copy ctor: "expected primary-expression before > token"

- by glutz78

Here's my code. It compiles in VS2005 but not in gcc. Any ideas template<class T> Derived<T>::Derived(const Derived<T>& in) { Base<T>::Base<T>(in); //ERROR here } "expected primary-expression before token"

Read the article

Core Data error when assigning variable with one-to-one relationship

- by Hoang Pham

Read the article

Can I get a C++ Compiler to instantiate objects at compile time

- by gam3

I am writing some code that has a very large number of reasonably simple objects and I would like them the be created at compile time. I would think that a compiler would be able to do this, but I have not been able to figure out how. In C I could do the the following: #include <stdio.h> typedef struct data_s { int a; int b; char *c; } info; info list[] = { 1, 2, "a", 3, 4, "b", }; main() { int i; for (i = 0; i < sizeof(list)/sizeof(*list); i++) { printf("%d %s\n", i, list[i].c); } } Using #C++* each object has it constructor called rather than just being layed out in memory. #include <iostream> using std::cout; using std::endl; class Info { const int a; const int b; const char *c; public: Info(const int, const int, const char *); const int get_a() { return a; }; const int get_b() { return b; }; const char *get_c() const { return c; }; }; Info::Info(const int a, const int b, const char *c) : a(a), b(b), c(c) {}; Info list[] = { Info(1, 2, "a"), Info(3, 4, "b"), }; main() { for (int i = 0; i < sizeof(list)/sizeof(*list); i++) { cout << i << " " << list[i].get_c() << endl; } } I just don't see what information is not available for the compiler to completely instantiate these objects at compile time, so I assume I am missing something.

Read the article

Return a dynamic string from std::exception's `what`

- by Shtééf

I'm convinced at this point that I should be creating subclasses of std::exception for all my exception throwing needs. Now I'm looking at how to override the what method. The situation that I'm facing, it would be really handy if the string what returns be dynamic. Some pieces of code parse an XML file for example, and adding a position or line number to the error message is useful to me. What I'd like to know: what returns a const char *, which implies any catcher is likely not going to free the string. So I need some other place to store the result, but where would that be? (I need thread-safety.) what also includes throw() in its signature. While I can prevent my what from throwing anything, it seems to me that this method really isn't intended for anything too dynamic. If what is not the right place, then where should I be doing this instead?

Read the article

Delphi constants and references

- by Sambatyon

I want to pass constant references to functions in delphi, so I am sure that the referenced object won't change and to save time and memory. So I want to declare a function like function foo(var const Value : Bar) : Boolean; however this is not allowed. I thought constant values would be automatically sent as references. However I found out that it is not the case (getting the address of an object before sending it to the function gives me $12F50C and the address of the same object inside the function is $12F564) What can I do to send constant references?

Read the article

Why is passing a string literal into a char* arguament only sometimes a compiler error?

- by Brian Postow

I'm working in a C, and C++ program. We used to be compiling without the make-strings-writable option. But that was getting a bunch of warnings, so I turned it off. Then I got a whole bunch of errors of the form "Cannot convert const char* to char* in argmuent 3 of function foo". So, I went through and made a whole lot of changes to fix those. However, today, the program CRASHED because the literal "" was getting passed into a function that was expecting a char*, and was setting the 0th character to 0. It wasn't doing anything bad, just trying to edit a constant, and crashing. My question is, why wasn't that a compiler error? In case it matters, this was on a mac compiled with gcc-4.0.

Read the article

How to get rid of `deprecated conversion from string constant to ‘char*’` warnings in GCC?

- by Josh Matthews

So I'm working on an exceedingly large codebase, and recently upgraded to gcc 4.3, which now triggers this warning: warning: deprecated conversion from string constant to ‘char*’ Obviously, the correct way to fix this is to find every declaration like char *s = "constant string"; or function call like void foo(char *s); foo("constant string"); and make them const char pointers. However, that would mean touching 564 files, minimum, which is not a task I wish to perform at this point in time. The problem right now is that I'm running with -werror, so I need some way to stifle these warnings. How can I do that?

Read the article

Turn class "Interfaceable"

- by scooterman

Hi folks, On my company system, we use a class to represent beans. It is just a holder of information using boost::variant and some serialization/deserialization stuff. It works well, but we have a problem: it is not over an interface, and since we use modularization through dlls, building an interface for it is getting very complicated, since it is used in almost every part of our app, and sadly interfaces (abstract classes ) on c++ have to be accessed through pointers, witch makes almost impossible to refactor the entire system. Our structure is: dll A: interface definition through abstract class dll B: interface implementation there is a painless way to achieve that (maybe using templates, I don't know) or I should forget about making this work and simply link everything with dll B? thanks Edit: Here is my example. this is on dll A BeanProtocol is a holder of N dataprotocol itens, wich are acessed by a index. class DataProtocol; class UTILS_EXPORT BeanProtocol { public: virtual DataProtocol& get(const unsigned int ) const { throw std::runtime_error("Not implemented"); } virtual void getFields(std::list<unsigned int>&) const { throw std::runtime_error("Not implemented"); } virtual DataProtocol& operator[](const unsigned int ) { throw std::runtime_error("Not implemented"); } virtual DataProtocol& operator[](const unsigned int ) const { throw std::runtime_error("Not implemented"); } virtual void fromString(const std::string&) { throw std::runtime_error("Not implemented"); } virtual std::string toString() const { throw std::runtime_error("Not implemented"); } virtual void fromBinary(const std::string&) { throw std::runtime_error("Not implemented"); } virtual std::string toBinary() const { throw std::runtime_error("Not implemented"); } virtual BeanProtocol& operator=(const BeanProtocol&) { throw std::runtime_error("Not implemented"); } virtual bool operator==(const BeanProtocol&) const { throw std::runtime_error("Not implemented"); } virtual bool operator!=(const BeanProtocol&) const { throw std::runtime_error("Not implemented"); } virtual bool operator==(const char*) const { throw std::runtime_error("Not implemented"); } virtual bool hasKey(unsigned int field) const { throw std::runtime_error("Not implemented"); } }; the other class (named GenericBean) implements it. This is the only way I've found to make this work, but now I want to turn it in a truly interface and remove the UTILS_EXPORT (which is an _declspec macro), and finally remove the forced linkage of B with A.

Read the article

How do I tell gcc to relax its restrictions on typecasting when calling a C function from C++?

- by Daryl Spitzer

I'm trying to use Cmockery to mock C functions called from C++ code. Because the SUT is in C++, my tests need to be in C++. When I use the Cmockery expect_string() macro like this: expect_string(mock_function, url, "Foo"); I get: my_tests.cpp: In function ‘void test_some_stuff(void**)’: my_tests.cpp:72: error: invalid conversion from ‘void*’ to ‘const char*’ my_tests.cpp:72: error: initializing argument 5 of ‘void _expect_string(const char*, const char*, const char*, int, const char*, int)’ I see in cmockery.h that expect_string is defined: #define expect_string(function, parameter, string) \ expect_string_count(function, parameter, string, 1) #define expect_string_count(function, parameter, string, count) \ _expect_string(#function, #parameter, __FILE__, __LINE__, (void*)string, \ count) And here's the prototype for _expect_string (from cmockery.h): void _expect_string( const char* const function, const char* const parameter, const char* const file, const int line, const char* string, const int count); I believe the problem is that I'm compiling C code as C++, so the C++ compiler is objecting to (void*)string in the expect_string_count macro being passed as the const char* string parameter to the _expect_string() function. I've already used extern "C" around the cmockery.h include in my_tests.cpp like this: extern "C" { #include <cmockery.h> } ...in order to get around name-mangling problems. (See "How do I compile and link C++ code with compiled C code?") Is there a command-line option or some other means of telling g++ how to relax its restrictions on typecasting from my test's C++ code to the C function in cmockery.c? This is the command I'm currently using to build my_tests.cpp: g++ -m32 -I ../cmockery-0.1.2 -c my_tests.cpp -o $(obj_dir)/my_tests.o

Read the article

Trying to compile a linux-based app on Mac OS X

- by Scott

I'm just trying to compile the linux-based FCEUX (NES emulator) on my mac, OS X 10.5 Leopard. I got all the dependencies (SDL, GTK+ 2) going and everything but of all things this is now my problem: Undefined symbols: "_compress", referenced from: SaveSnapshot() in video.o "_gzclose", referenced from: FCEU_fopen(char const*, char const*, char*, char*, int, char const**)in file.o "_crc32", referenced from: CalcCRC32(unsigned int, unsigned char*, unsigned int)in crc32.o _unzReadCurrentFile in unzip.o _unzReadCurrentFile in unzip.o "_uncompress", referenced from: NetplayUpdate(unsigned char*)in netplay.o FCEUSS_LoadFP(EMUFILE*, ENUM_SSLOADPARAMS) in state.o "_compress2", referenced from: FCEUNET_SendFile(unsigned char, char*)in netplay.o FCEUSS_SaveMS(EMUFILE*, int) in state.o "_inflateEnd", referenced from: _unzCloseCurrentFile in unzip.o "_inflate", referenced from: _unzReadCurrentFile in unzip.o "inflateInit2", referenced from: _unzOpenCurrentFile in unzip.o "_gzgetc", referenced from: FCEU_fopen(char const*, char const*, char*, char*, int, char const**)in file.o "_gzopen", referenced from: FCEU_fopen(char const*, char const*, char*, char*, int, char const**)in file.o "_gzread", referenced from: FCEU_fopen(char const*, char const*, char*, char*, int, char const**)in file.o "_gzseek", referenced from: FCEU_fopen(char const*, char const*, char*, char*, int, char const*)in file.o ld: symbol(s) not found collect2: ld returned 1 exit status scons: ** [src/fceux] Error 1 scons: building terminated because of errors. Those are zlib functions. It seems like it is loading the zlib.h ok, but the symbols aren't being linked in? Just to make sure I downloaded the latest zlib and did a make install, no help. I have no clue what's going on here, it seems like it should be pretty basic, that library is nothing special. Help would be appreciated. Thanks.

Read the article

Java: How can a constructor return a value?

- by HH

$ cat Const.java public class Const { String Const(String hello) { return hello; } public static void main(String[] args) { System.out.println(new Const("Hello!")); } } $ javac Const.java Const.java:7: cannot find symbol symbol : constructor Const(java.lang.String) location: class Const System.out.println(new Const("Hello!")); ^ 1 error

Read the article

How does the compile choose which template function to call?

- by aCuria

Regarding the below code, how does the compiler choose which template function to call? If the const T& function is omitted, the T& function is always called. If the T& function is omitted, the const T& function is always called. If both are included, the results are as below. #include <iostream> #include <typeinfo> template <typename T> void function(const T &t) { std::cout << "function<" << typeid(T).name() << ">(const T&) called with t = " << t << std::endl; } template <typename T> void function(T &t) { std::cout << "function<" << typeid(T).name() << ">(T&) called with t = " << t << std::endl; } int main() { int i1 = 57; const int i2 = -6; int *pi1 = &i1; int *const pi3 = &i1; const int *pi2 = &i2; const int *const pi4 = &i2; function(pi1); ///just a normal pointer -> T& function(pi2); ///cannot change what we point to -> T& function(pi3); ///cannot change where we point -> const T& function(pi4); ///cannot change everything -> const T& return 0; } /* g++ output: function<Pi>(T&) called with t = 0x22cd24 function<PKi>(T&) called with t = 0x22cd20 function<Pi>(const T&) called with t = 0x22cd24 function<PKi>(const T&) called with t = 0x22cd20 */ /* bcc32 output: function<int *>(T&) called with t = 0012FF50 function<const int *>(T&) called with t = 0012FF4C function<int *>(const T&) called with t = 0012FF50 function<const int *>(const T&) called with t = 0012FF4C */ /* cl output: function<int *>(T&) called with t = 0012FF34 function<int const *>(T&) called with t = 0012FF28 function<int *>(const T&) called with t = 0012FF34 function<int const *>(const T&) called with t = 0012FF28 */

Read the article

How to hide/show a Process using c#?

- by aF

Hello, While executing my program, I want to hide/minimize Microsoft Speech Recognition Application: and at the end I want to show/maximize using c#! This process is not started by me so I can't give control the process startInfo. I've tried to use user32.dll methods such as: ShowWindow AnimatedWindows AnimatedWindows With all of them I have the same problem. I can hide the windows (althought I have to call one of the methods two times with SW_HIDE option), but when I call the method with a SW_SHOW flag, it simply doesn't shows.. How can I maximize/show after hiding the process? Thanks in advance! Here is some pieces of the code, now implemented to use SetWindowPlacement: { [DllImport("user32.dll")] [return: MarshalAs(UnmanagedType.Bool)] public static extern bool GetWindowPlacement(IntPtr hWnd, ref WINDOWPLACEMENT lpwndpl); [DllImport("user32.dll", SetLastError = true)] [return: MarshalAs(UnmanagedType.Bool)] static extern bool SetWindowPlacement(IntPtr hWnd, [In] ref WINDOWPLACEMENT lpwndpl); [DllImport("user32.dll")] public static extern Boolean ShowWindowAsync(IntPtr hWnd, Int32 nCmdShow); [DllImport("user32.dll")] public static extern Boolean SetForegroundWindow(IntPtr hWnd); [DllImport("user32.dll")] public static extern Boolean ShowWindow(IntPtr hWnd, Int32 nCmdShow); [DllImport("user32.dll")] public static extern Boolean AnimateWindow(IntPtr hWnd, uint dwTime, uint dwFlags); [DllImport("dwmapi.dll")] public static extern int DwmSetWindowAttribute(IntPtr hwnd, uint dwAttribute, IntPtr pvAttribute, IntPtr lol); //Definitions For Different Window Placement Constants const UInt32 SW_HIDE = 0; const UInt32 SW_SHOWNORMAL = 1; const UInt32 SW_NORMAL = 1; const UInt32 SW_SHOWMINIMIZED = 2; const UInt32 SW_SHOWMAXIMIZED = 3; const UInt32 SW_MAXIMIZE = 3; const UInt32 SW_SHOWNOACTIVATE = 4; const UInt32 SW_SHOW = 5; const UInt32 SW_MINIMIZE = 6; const UInt32 SW_SHOWMINNOACTIVE = 7; const UInt32 SW_SHOWNA = 8; const UInt32 SW_RESTORE = 9; public sealed class AnimateWindowFlags { public const int AW_HOR_POSITIVE = 0x00000001; public const int AW_HOR_NEGATIVE = 0x00000002; public const int AW_VER_POSITIVE = 0x00000004; public const int AW_VER_NEGATIVE = 0x00000008; public const int AW_CENTER = 0x00000010; public const int AW_HIDE = 0x00010000; public const int AW_ACTIVATE = 0x00020000; public const int AW_SLIDE = 0x00040000; public const int AW_BLEND = 0x00080000; } public struct WINDOWPLACEMENT { public int length; public int flags; public int showCmd; public System.Drawing.Point ptMinPosition; public System.Drawing.Point ptMaxPosition; public System.Drawing.Rectangle rcNormalPosition; } //this works param = new WINDOWPLACEMENT(); param.length = Marshal.SizeOf(typeof(WINDOWPLACEMENT)); param.showCmd = (int)SW_HIDE; lol = SetWindowPlacement(theprocess.MainWindowHandle, ref param); // this doesn't work WINDOWPLACEMENT param = new WINDOWPLACEMENT(); param.length = Marshal.SizeOf(typeof(WINDOWPLACEMENT)); param.showCmd = SW_SHOW; lol = GetWindowPlacement(theprocess.MainWindowHandle, ref param);

Read the article

visual tool to resolve conflicts merged into a single file

- by Yehosef

I did a git merge and ended up with a file like that looks like this: class member extends item{ /********CONSTANTS**********/ const is_flaggable = true; const is_commentable = false; const is_ratable = false; const table = 'member'; <<<<<<< HEAD const table_about = 'mem_about' ; const table_to_about = 'mem_to_about' ; const table_hobbies = 'mem_to_hobby'; ======= const table_friendship = 'friendship'; const table_about = 'mem_about' ; const table_to_about = 'mem_to_about' ; const table_hobbies = 'mem_to_hobby'; const table_friendship_id = 3; >>>>>>> my-copy In this file there are many blocks like this. Is there a visual tool to help me look at this file and pick and choose the changes I want? Most of the diff tools I found are for looking at two files.

Read the article

Const_cast on a this pointer - would I get told off by other C++ coders for doing this?

- by BeeBand

I have a class Game e.g. class Game { public: InitObjects(); ... }; And I have another class Grid, that needs to be initialised with a non-const reference to that Game object. ( A Grid object needs to call functions that can update a Game object ). class Grid { public: Grid(Game & g): game(g){} ... private: Game & game; ... }; The Game object is responsible for initialising the Grid. I did this: void Game::InitObjects() { grid = new Grid(*(const_cast<Game*>(this)) ); } grid is not a member of a Game - it's a global ( argh - i know... I don't mind making it a member, but I have the same problem right? ). Can some seasoned C++ folk tell me if this odd looking const_cast is acceptable?

Read the article

Why is passing a string literal into a char* argument only sometimes a compiler error?

- by Brian Postow

I'm working in a C, and C++ program. We used to be compiling without the make-strings-writable option. But that was getting a bunch of warnings, so I turned it off. Then I got a whole bunch of errors of the form "Cannot convert const char* to char* in argmuent 3 of function foo". So, I went through and made a whole lot of changes to fix those. However, today, the program CRASHED because the literal "" was getting passed into a function that was expecting a char*, and was setting the 0th character to 0. It wasn't doing anything bad, just trying to edit a constant, and crashing. My question is, why wasn't that a compiler error? In case it matters, this was on a mac compiled with gcc-4.0. EDIT: added code: char * host = FindArgDefault("EMailLinkHost", ""); stripCRLF(linkHost, '\n'); where: char *FindArgDefault(char *argName, char *defVal) {// simplified char * val = defVal; return(val); } and void stripCRLF(char *str, char delim) { char *p, *q; for (p = q = str; *p; ++p) { if (*p == 0xd || *p == 0xa) { if (p[1] == (*p ^ 7)) ++p; if (delim == -1) *p = delim; } *q++ = *p; } *q = 0; // DIES HERE } This compiled and ran until it tried to set *q to 0...

Read the article

C++ iterator and const_iterator problem for own container class

- by BaCh

Hi there, I'm writing an own container class and have run into a problem I can't get my head around. Here's the bare-bone sample that shows the problem. It consists of a container class and two test classes: one test class using a std:vector which compiles nicely and the second test class which tries to use my own container class in exact the same way but fails miserably to compile. #include <vector> #include <algorithm> #include <iterator> using namespace std; template <typename T> class MyContainer { public: class iterator { public: typedef iterator self_type; inline iterator() { } }; class const_iterator { public: typedef const_iterator self_type; inline const_iterator() { } }; iterator begin() { return iterator(); } const_iterator begin() const { return const_iterator(); } }; // This one compiles ok, using std::vector class TestClassVector { public: void test() { vector<int>::const_iterator I=myc.begin(); } private: vector<int> myc; }; // this one fails to compile. Why? class TestClassMyContainer { public: void test(){ MyContainer<int>::const_iterator I=myc.begin(); } private: MyContainer<int> myc; }; int main(int argc, char ** argv) { return 0; } gcc tells me: test2.C: In member function ‘void TestClassMyContainer::test()’: test2.C:51: error: conversion from ‘MyContainer::iterator’ to non-scalar type ‘MyContainer::const_iterator’ requested I'm not sure where and why the compiler wants to convert an iterator to a const_iterator for my own class but not for the STL vector class. What am I doing wrong?

Read the article

C++ HW - defining classes - objects that have objects of other class problem in header file (out of

- by kitfuntastik

This is my first time with much of this code. With this instancepool.h file below I get errors saying I can't use vector (line 14) or have instance& as a return type (line 20). It seems it can't use the instance objects despite the fact that I have included them. #ifndef _INSTANCEPOOL_H #define _INSTANCEPOOL_H #include "instance.h" #include <iostream> #include <string> #include <vector> #include <stdlib.h> using namespace std; class InstancePool { private: unsigned instances;//total number of instance objects vector<instance> ipp;//the collection of instance objects, held in a vector public: InstancePool();//Default constructor. Creates an InstancePool object that contains no Instance objects InstancePool(const InstancePool& original);//Copy constructor. After copying, changes to original should not affect the copy that was created. ~InstancePool();//Destructor unsigned getNumberOfInstances() const;//Returns the number of Instance objects the the InstancePool contains. const instance& operator[](unsigned index) const; InstancePool& operator=(const InstancePool& right);//Overloading the assignment operator for InstancePool. friend istream& operator>>(istream& in, InstancePool& ip);//Overloading of the >> operator. friend ostream& operator<<(ostream& out, const InstancePool& ip);//Overloading of the << operator. }; #endif Here is the instance.h : #ifndef _INSTANCE_H #define _INSTANCE_H ///////////////////////////////#include "instancepool.h" #include <iostream> #include <string> #include <stdlib.h> using namespace std; class Instance { private: string filenamee; bool categoryy; unsigned featuress; unsigned* featureIDD; unsigned* frequencyy; string* featuree; public: Instance (unsigned features = 0);//default constructor unsigned getNumberOfFeatures() const; //Returns the number of the keywords that the calling Instance object can store. Instance(const Instance& original);//Copy constructor. After copying, changes to the original should not affect the copy that was created. ~Instance() { delete []featureIDD; delete []frequencyy; delete []featuree;}//Destructor. void setCategory(bool category){categoryy = category;}//Sets the category of the message. Spam messages are represented with true and and legit messages with false.//easy bool getCategory() const;//Returns the category of the message. void setFileName(const string& filename){filenamee = filename;}//Stores the name of the file (i.e. “spam/spamsga1.txt”, like in 1st assignment) in which the message was initially stored.//const string& trick? string getFileName() const;//Returns the name of the file in which the message was initially stored. void setFeature(unsigned i, const string& feature, unsigned featureID,unsigned frequency) {//i for array positions featuree[i] = feature; featureIDD[i] = featureID; frequencyy[i] = frequency; } string getFeature(unsigned i) const;//Returns the keyword which is located in the ith position.//const string unsigned getFeatureID(unsigned i) const;//Returns the code of the keyword which is located in the ith position. unsigned getFrequency(unsigned i) const;//Returns the frequency Instance& operator=(const Instance& right);//Overloading of the assignment operator for Instance. friend ostream& operator<<(ostream& out, const Instance& inst);//Overloading of the << operator for Instance. friend istream& operator>>(istream& in, Instance& inst);//Overloading of the >> operator for Instance. }; #endif Also, if it is helpful here is instance.cpp: // Here we implement the functions of the class apart from the inline ones #include "instance.h" #include <iostream> #include <string> #include <stdlib.h> using namespace std; Instance::Instance(unsigned features) { //Constructor that can be used as the default constructor. featuress = features; if (features == 0) return; featuree = new string[featuress]; // Dynamic memory allocation. featureIDD = new unsigned[featuress]; frequencyy = new unsigned[featuress]; return; } unsigned Instance::getNumberOfFeatures() const {//Returns the number of the keywords that the calling Instance object can store. return featuress;} Instance::Instance(const Instance& original) {//Copy constructor. filenamee = original.filenamee; categoryy = original.categoryy; featuress = original.featuress; featuree = new string[featuress]; for(unsigned i = 0; i < featuress; i++) { featuree[i] = original.featuree[i]; } featureIDD = new unsigned[featuress]; for(unsigned i = 0; i < featuress; i++) { featureIDD[i] = original.featureIDD[i]; } frequencyy = new unsigned[featuress]; for(unsigned i = 0; i < featuress; i++) { frequencyy[i] = original.frequencyy[i];} } bool Instance::getCategory() const { //Returns the category of the message. return categoryy;} string Instance::getFileName() const { //Returns the name of the file in which the message was initially stored. return filenamee;} string Instance::getFeature(unsigned i) const { //Returns the keyword which is located in the ith position.//const string return featuree[i];} unsigned Instance::getFeatureID(unsigned i) const { //Returns the code of the keyword which is located in the ith position. return featureIDD[i];} unsigned Instance::getFrequency(unsigned i) const { //Returns the frequency return frequencyy[i];} Instance& Instance::operator=(const Instance& right) { //Overloading of the assignment operator for Instance. if(this == &right) return *this; delete []featureIDD; delete []frequencyy; delete []featuree; filenamee = right.filenamee; categoryy = right.categoryy; featuress = right.featuress; featureIDD = new unsigned[featuress]; frequencyy = new unsigned[featuress]; featuree = new string[featuress]; for(unsigned i = 0; i < featuress; i++) { featureIDD[i] = right.featureIDD[i]; } for(unsigned i = 0; i < featuress; i++) { frequencyy[i] = right.frequencyy[i]; } for(unsigned i = 0; i < featuress; i++) { featuree[i] = right.featuree[i]; } return *this; } ostream& operator<<(ostream& out, const Instance& inst) {//Overloading of the << operator for Instance. out << endl << "<message file=" << '"' << inst.filenamee << '"' << " category="; if (inst.categoryy == 0) out << '"' << "legit" << '"'; else out << '"' << "spam" << '"'; out << " features=" << '"' << inst.featuress << '"' << ">" <<endl; for (int i = 0; i < inst.featuress; i++) { out << "<feature id=" << '"' << inst.featureIDD[i] << '"' << " freq=" << '"' << inst.frequencyy[i] << '"' << "> " << inst.featuree[i] << " </feature>"<< endl; } out << "</message>" << endl; return out; } istream& operator>>(istream& in, Instance& inst) { //Overloading of the >> operator for Instance. string word; string numbers = ""; string filenamee2 = ""; bool categoryy2 = 0; unsigned featuress2; string featuree2; unsigned featureIDD2; unsigned frequencyy2; unsigned i; unsigned y; while(in >> word) { if (word == "<message") {//if at beginning of message in >> word;//grab filename word for (y=6; word[y]!='"'; y++) {//pull out filename from between quotes filenamee2 += word[y];} in >> word;//grab category word if (word[10] == 's') categoryy2 = 1; in >> word;//grab features word for (y=10; word[y]!='"'; y++) { numbers += word[y];} featuress2 = atoi(numbers.c_str());//convert string of numbers to integer Instance tempp2(featuress2);//make a temporary Instance object to hold values read in tempp2.setFileName(filenamee2);//set temp object to filename read in tempp2.setCategory(categoryy2); for (i=0; i<featuress2; i++) {//loop reading in feature reports for message in >> word >> word >> word;//skip two words numbers = "";//reset numbers string for (int y=4; word[y]!='"'; y++) {//grab feature ID numbers += word[y];} featureIDD2 = atoi(numbers.c_str()); in >> word;// numbers = ""; for (int y=6; word[y]!='"'; y++) {//grab frequency numbers += word[y];} frequencyy2 = atoi(numbers.c_str()); in >> word;//grab actual feature string featuree2 = word; tempp2.setFeature(i, featuree2, featureIDD2, frequencyy2); }//all done reading in and setting features in >> word;//read in last part of message : </message> inst = tempp2;//set inst (reference) to tempp2 (tempp2 will be destroyed at end of function call) return in; } } } and instancepool.cpp: // Here we implement the functions of the class apart from the inline ones #include "instancepool.h" #include "instance.h" #include <iostream> #include <string> #include <vector> #include <stdlib.h> using namespace std; InstancePool::InstancePool()//Default constructor. Creates an InstancePool object that contains no Instance objects { instances = 0; ipp.clear(); } InstancePool::~InstancePool() { ipp.clear();} InstancePool::InstancePool(const InstancePool& original) {//Copy constructor. instances = original.instances; for (int i = 0; i<instances; i++) { ipp.push_back(original.ipp[i]); } } unsigned InstancePool::getNumberOfInstances() const {//Returns the number of Instance objects the the InstancePool contains. return instances;} const Instance& InstancePool::operator[](unsigned index) const {//Overloading of the [] operator for InstancePool. return ipp[index];} InstancePool& InstancePool::operator=(const InstancePool& right) {//Overloading the assignment operator for InstancePool. if(this == &right) return *this; ipp.clear(); instances = right.instances; for(unsigned i = 0; i < instances; i++) { ipp.push_back(right.ipp[i]); } return *this; } istream& operator>>(istream& in, InstancePool& ip) {//Overloading of the >> operator. ip.ipp.clear(); string word; string numbers; int total;//int to hold total number of messages in collection while(in >> word) { if (word == "<messagecollection"){ in >> word;//reads in total number of all messages for (int y=10; word[y]!='"'; y++){ numbers = ""; numbers += word[y]; } total = atoi(numbers.c_str()); for (int x = 0; x<total; x++) {//do loop for each message in collection in >> ip.ipp[x];//use instance friend function and [] operator to fill in values and create Instance objects and read them intot he vector } } } } ostream& operator<<(ostream& out, const InstancePool& ip) {//Overloading of the << operator. out << "<messagecollection messages=" << '"' << '>' << ip.instances << '"'<< endl << endl; for (int z=0; z<ip.instances; z++) { out << ip[z];} out << endl<<"</messagecollection>\n"; } This code is currently not writing to files correctly either at least, I'm sure it has many problems. I hope my posting of so much is not too much, and any help would be very much appreciated. Thanks!

Read the article

Why is it that I can include a header file in multiple cpp files that contains const int and not have a compiler error?

- by tree

Let's assume that I have files a.cpp b.cpp and file c.h. Both of the cpp files include the c.h file. The header file contains a bunch of const int definitions and when I compile them I get no errors and yet I can access those const as if they were global variables. So the question, why don't I get any compilation errors if I have multiple const definitions as well as these const int's having global-like scope?

Read the article

Template problems: No matching function for call

- by Nick Sweet

I'm trying to create a template class, and when I define a non-member template function, I get the "No matching function for call to randvec()" error. I have a template class defined as: template <class T> class Vector { T x, y, z; public: //constructors Vector(); Vector(const T& x, const T& y, const T& z); Vector(const Vector& u); //accessors T getx() const; T gety() const; T getz() const; //mutators void setx(const T& x); void sety(const T& y); void setz(const T& z); //operations void operator-(); Vector plus(const Vector& v); Vector minus(const Vector& v); Vector cross(const Vector& v); T dot(const Vector& v); void times(const T& s); T length() const; //Vector<T>& randvec(); //operators Vector& operator=(const Vector& rhs); friend std::ostream& operator<< <T>(std::ostream&, const Vector<T>&); }; and the function in question, which I've defined after all those functions above, is: //random Vector template <class T> Vector<double>& randvec() { const int min=-10, max=10; Vector<double>* r = new Vector<double>; int randx, randy, randz, temp; const int bucket_size = RAND_MAX/(max-min +1); temp = rand(); //voodoo hackery do randx = (rand()/bucket_size)+min; while (randx < min || randx > max); r->setx(randx); do randy = (rand()/bucket_size)+min; while (randy < min || randy > max); r->sety(randy); do randz = (rand()/bucket_size)+min; while (randz < min || randz > max); r->setz(randz); return *r; } Yet, every time I call it in my main function using a line like: Vector<double> a(randvec()); I get that error. However, if I remove the template and define it using 'double' instead of 'T', the call to randvec() works perfectly. Why doesn't it recognize randvec()? P.S. Don't mind the bit labeled voodoo hackery - this is just a cheap hack so that I can get around another problem I encountered.

Read the article

Are there constants in Javascript?

- by fuentesjr

If not, what's the common practice for specifying variables that are used as constants?

Read the article

If-elseif-else Logic Question

- by Changeling

I have a set of three values, call them x, y, and z. If value A happens to match only one in the set x, y, and z, then that means we have a proper match and we stop searching for a match, even if it is at y. It can match any one in that set. These values x, y, and z are non-constant so I cannot use a switch-case statement. How do I do this with an if-elseif-else statements without having to use GOTO. I am using C++ (no boost or any of that other fancy stuff). Now, I am trying to do this in code and it is racking my brain this morning (not enough coffee?)

Read the article

Shall I prefer constants over defines?

- by Helper Method

In C, shall I prefer constants over defines? I've reading a lot of code lately, and all of the examples make heavy use of defines.

Read the article

Correct usage(s) of const_cast<>

- by ereOn

Hi, As a common rule, it is very often considered a bad practice to use const_cast<>() in C++ code as it reveals (most of the time) a flaw in the design. While I totally agree with this, I however wonder what are the cases were using const_cast<>() is ok and the only solution. Could you guys please give me some examples you know/you encountered ? Thank you very much.

Search Results

Search found 3389 results on 136 pages for 'const'.

Page 11/136 | < Previous Page | 7 8 9 10 11 12 13 14 15 16 17 18 | Next Page >

- by zproxy

- by glutz78

- by Hoang Pham

- by gam3

- by Shtééf

- by Sambatyon

- by Brian Postow

- by Josh Matthews

- by scooterman

- by Daryl Spitzer

- by Scott

- by HH

- by aCuria

- by aF

- by Yehosef

- by BeeBand

- by Brian Postow

- by BaCh

- by kitfuntastik

- by tree

- by Nick Sweet

- by fuentesjr

- by Changeling

- by Helper Method

- by ereOn

< Previous Page | 7 8 9 10 11 12 13 14 15 16 17 18 | Next Page >