i know using namespace std; is important to wite as it contain cout,cin,etc........but is that namespace std is contained inside iostream header file OR iostream header file is contained inside namespace std ......
View 1 RepliesIt seems as though more experienced programmers tend to write code with std::cout, std::string, etc., whereas less experienced programmers always write using namespace std;. They also tend to assume that, in code snips, it is already included.
Why is this? If it's a dislike, what's the problem with it? As stated in the namespaces tutorial on this site, a namespace can be overridden if need be. Is it the case that you have written your own namespaces? Or that you so seldom use things like the STL and stdin/out that it just isn't necessary?
#include<iostream>
#include<conio>
nmaespace num {
void disp(int x) {
[Code] ....
Can we put using namespace std; in a header file? Someone told me not to do it, but I don't know why...
View 2 Replies View RelatedI have two header files, A, B.
A.h
namespace test {
struct info
{
int a;
}
}
B.h
#include "A.h"
int main {
test::info.a = 10;
}
However, it has an error. I don't quite understand how to use namespace.
exportmain.cpp
Code:
#include <boost/property_tree/ptree.hpp>
#include <boost/property_tree/xml_parser.hpp>
// Create an empty property tree object
using boost::property_tree::ptree;
#include "kwxport.h"
#include "resource.h"
[Code] ....
How can I make boost:roperty_tree:tree get recognized by the compiler?
What is difference between an class and an namespace? You can put functions in both class and namespace?
View 1 Replies View RelatedI've verified this on ubuntu 12.10 and on windows/mingw, and found that g++ version 4.7.2 seems to have broken thread/mutex support.
View 11 Replies View RelatedWhy is using namespace needed in linux but not in turbo c++?
View 1 Replies View RelatedI want to create a namespace named MyNS.
Can I define it in multiple files?
I mean:
file1.h
namespace MyNS {
const int File1 = 0;
} file2.h
namespace MyNS {
const int File2 = 1;
[Code] .....
I have two files that I want to compile:
main.cpp
Code:
#include <iostream>
using namespace std;
int ReadNumber();
void WriteAnswer();
[Code] .....
The compiler complains:
io.cpp||In function 'int ReadNumber()':|
io.cpp|3|error: 'cin' was not declared in this scope|
io.cpp||In function 'void WriteAnswer()':|
io.cpp|7|error: 'cout' was not declared in this scope|
io.cpp|7|error: 'endl' was not declared in this scope|
In io.cpp file, should I put the two statements ("include <iostream>" and "using namespace std") at the top, outside of the functions?
Or should I put the two statements inside each of the functions?
I'm trying to make a class constructor within a namespace and I keep getting errors like: "'<variable>' is a nonstatic data member of class '<class>'" for when I try to setup parameters, and "Incomplete type is not allow" whenever I try to write out my function definition. Here's what I'm doing:
namespace test {
class blah;
} class blah {
typedef int var[5];
[Code] .....
Also I'm unsure why there is a parameter of 'const blah &' when I mouse over blah(); (using Visual Studio 2010) within the class definition. It tells me 'blah::blah(const blah &)' and I am unsure where the parameter comes from. How can I resolve these issues?
I am creating a logging namespace for a game that I am creating. The logging includes a file, and it would contain the following methods:
OUT::log(?)
OUT::warn(?)
OUT::critical(?)
OUT::debug(?)
I will want to call things like
OUT::log("Something happened");
and
OUT::log("Code process " + int proc + " occurred.");
But this might have to be changed to something like
OUT::log("Code process ", int proc, " occurred.");
What would I put in place of "?" to accomplish this?
I don't want to create 30 different methods for this, ie, not
OUT::log(string, int, string);
OUT::log(string, long, string);
OUT::log(string, double, string);
OUT::log(string, int);
OUT::log(string, int, string, int, string);
...I do NOT want to do this...too much chaos. I understand in C++11, I could do something with int like to_string, and that would make the "string" + int + "string" to work.
I have created a Namespace Extension (I hope so) by creating a ATL Project with MFC support as dll in Visual Studio 2010.
Now I have a Implementation of IShellFolder:
Code:
// ILCShellFolder.h: Deklaration von CILCShellFolder
#pragma once
#include "resource.h" // Hauptsymbole
#include "NewNSE_i.h"
#if defined(_WIN32_WCE) && !defined(_CE_DCOM) && !defined(_CE_ALLOW_SINGLE_THREADED_OBJECTS_IN_MTA)
[Code] ....
Not any of those IShellFolder Methods is being called... When I attach the explorer.exe process (which I know I can use to debug on other projects, just in case to exclude errors) it tells me that the DLL is not loaded by the explorer.exe process.
I am trying to test out stoi() function found in the link below.
[URL] ....
but I got the error "No Member named stoi in namespace std." ...
I have an advanced data namespace in which I hope to be able to read a data variable of any type and transfer it's bytes into another type of a multiple size.
i.e.
char[4] -> int;
int -> short[2];
short -> char[2];
char[2] -> short;
but I'm having some trouble, I get the following errors (because as a template it must compile from start)
template<typename T1, typename T2> void stepBytes(UCHAR size1, UCHAR size2, T1 in, T2& out){
if(size1 == 0 || size2 == 0)
return;
if(size1 % size2 != 0 &&
size2 % size1 != 0)
[Code] ....
So, why's this error appearing?
I know how to make a namespace i just want to know why someone would. because it just seems like a way to show a bunch of variables and functions into a compact area.
View 3 Replies View RelatedWrite a program to generate a report based on input received from a text file. Suppose the input text file student_status.txt contains the student’s name (lastName, firstName middleName), id, number of credits earned as follows :
Doe, John K.
3460 25
Andrews, Susan S.
3987 72
Monroe, Marylin
2298 87
Gaston, Arthur C.
2894 110
Generate the output in the following format :
John K. Doe 3460 25 Freshman
Susan S. Andrews 3987 40 Sophomore
Marylin Monroe 2298 87 Junior
Arthur C. Gaston 2894 110 Senior
The program must be written to use the enum class_level :
enum class_level {FRESHMAN, SOPHOMORE, JUNIOR, SENIOR } ;
and define two namespace globalTypes (tys and fys) for the function :
class_level deriveClassLevel(int num_of_credits) ;
The function deriveClassLevel should derive the class_level of the student based on the number of credits earned.
The first namespace globalType tys should derive the class level based on a two year school policy.
and the second namespace globalType fys should derive the class level based on a four year school policy.
Four Year School Policy:
Freshman 0-29 creditsSophomore 30-59 credits
Junior 60-89 creditsSenior 90 or more credits
Two Year School Policy:
Freshman 0-29 creditsSophomore 30 or more credits
NOTE : use ignore() function with ifstream objects whenever you want to ignore the newline character.
For example :
ifstream transferSchoolFile ;
transferSchoolFile.open("student_status.txt", ios::in);
while( !transferSchoolFile.eof()) {
getline(transferSchoolFile,name) ;
transferSchoolFile >> id >> credits;
transferSchoolFile.ignore(); //Used here to ignore the newline character.
….
}
I did this in parts so I got it working with a four year criteria without the user defined name spaces.
include <iostream>
#include <fstream>
#include <string>
using namespace std;
enum class_level { FRESHMAN, SOPHOMORE, JUNIOR, SENIOR };
[Code] ....
So that worked fine then I tried with name spaces -
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
enum class_level { FRESHMAN, SOPHOMORE, JUNIOR, SENIOR };
class_level classLevel;
[Code] ....
I know I have some stuff to mess around with but I am currently stuck with two errors, first -
Error1error LNK2019: unresolved external symbol _main referenced in function ___tmainCRTStartupC:UsersstephenDocumentsVisual Studio 2013ProjectsinputConsoleApplication1MSVCRTD.lib(crtexe.obj)ConsoleApplication1
then -
Error2error LNK1120: 1 unresolved externalsC:UsersstephenDocumentsVisual Studio 2013ProjectsinputDebugConsoleApplication1.exeConsoleApplication1
Program Description: Write a program to generate a report based on input received from a text file. Suppose the input text file student_status.txt contains the student's name (lastName, firstName middleName), id, number of credits earned as follows :
Doe, John K.
3460 25
Andrews, Susan S.
3987 72
Monroe, Marylin
2298 87
Gaston, Arthur C.
2894 110
Generate the output in the following format :
John K. Doe 3460 25 Freshman
Susan S. Andrews 3987 40 Sophomore
Marylin Monroe 2298 87 Junior
Arthur C. Gaston 2894 110 Senior
The program must be written to use the enum class_level :
enum class_level {FRESHMAN, SOPHOMORE, JUNIOR, SENIOR } ;
and define two namespace globalTypes (tys and fys) for the function :
class_level deriveClassLevel(int num_of_credits) ;
The function deriveClassLevel should derive the class_level of the student based on the number of credits earned.
The first namespace globalType tys should derive the class level based on a two year school policy.
and the second namespace globalType fys should derive the class level based on a four year school policy.
Four Year School Policy:
Freshman 0-29 creditsSophomore 30-59 credits
Junior 60-89 creditsSenior 90 or more credits
Two Year School Policy:
Freshman 0-29 creditsSophomore 30 or more credits
NOTE : use ignore() function with ifstream objects whenever you want to ignore the newline character. For example :
ifstream transferSchoolFile ;
transferSchoolFile.open("student_status.txt", ios::in);
while( !transferSchoolFile.eof()) {
getline(transferSchoolFile,name) ;
transferSchoolFile >> id >> credits;
[Code] ....
I know I have some stuff to mess around with but I am currently stuck with two errors, first -
Error1error LNK2019: unresolved external symbol _main referenced in function ___tmainCRTStartupC:UsersstephenDocumentsVisual Studio 2013ProjectsinputConsoleApplication1MSVCRTD.lib(crtexe.obj)ConsoleApplication1
then -
Error2error LNK1120: 1 unresolved externalsC:UsersstephenDocumentsVisual Studio 2013ProjectsinputDebugConsoleApplication1.exeConsoleApplication1