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adding a queue to a class

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I'm attempting to add a queue as a private member of my class, but get the error " syntax error : missing ';' before '<' " on the line where it is declared, I would appreciate any insight into why I'm unable to compile.

here is an example of my code:
[source]
#include <queue>

class GameBoard{
private:
queue<int> upcomingPieces;
};
[/source] Edited by becklighter

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I'm attempting to add a queue as a private member of my class, but get the error " syntax error : missing ';' before '<' " on the line where it is declared, I would appreciate any insight into why I'm unable to compile.

here is an example of my code:
[source]
#include <queue>

class GameBoard{
private:
queue<int> upcomingPieces;
}
[/source]



#include <queue>

class GameBoard{
private:
queue<int> upcomingPieces;
}; // <---

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[quote name='becklighter' timestamp='1313360304' post='4849142']
I'm attempting to add a queue as a private member of my class, but get the error " syntax error : missing ';' before '<' " on the line where it is declared, I would appreciate any insight into why I'm unable to compile.

here is an example of my code:
[source]
#include <queue>

class GameBoard{
private:
queue<int> upcomingPieces;
}
[/source]



#include <queue>

class GameBoard{
private:
queue<int> upcomingPieces;
}; // <---

[/quote]

Thanks for pointing out that my class was missing the ";", but that isn't the problem. The code in my project actually had that part right, I just didn't copy it all over, any other ideas?

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[quote name='becklighter' timestamp='1313360304' post='4849142']
I'm attempting to add a queue as a private member of my class, but get the error " syntax error : missing ';' before '<' " on the line where it is declared, I would appreciate any insight into why I'm unable to compile.

here is an example of my code:
[source]
#include <queue>

class GameBoard{
private:
queue<int> upcomingPieces;
}
[/source]



#include <queue>

class GameBoard{
private:
queue<int> upcomingPieces;
}; // <---

[/quote]

and


#include <queue>

class GameBoard{
private:
std::queue<int> upcomingPieces; // <-- std::
};

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Hello :)

There are 2 options :
  • use std::queue instead of queue everywhere
  • or [s]put using namespace std; after the #include<queue>[/s] (sorry :()

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....as there is no way to "un-use" a namespace.


Why would you 'un-use' a namespace ?
std is used with vector, string,list,etc.... so putting std:: everywhere is not very elegant

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[quote name='rip-off' timestamp='1313394843' post='4849284']
....as there is no way to "un-use" a namespace.


Why would you 'un-use' a namespace ?
std is used with vector, string,list,etc.... so putting std:: everywhere is not very elegant
[/quote]


"using" a namespace in a header is bad.

What if I want to call something foo::string? If I #include your header, I now have a name collision between foo::string and std::string.

You should only be "using" namespaces from within .cpp files, preferably after all headers are included, and then only as absolutely necessary.

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What about inline classes ? Where else could you put the using directive ? Isn't it a bad idea to call a class 'string' anyway ?

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std is used with vector, string,list,etc.... so putting std:: everywhere is not very elegant
A standard C++ rule, that's in almost every C++ style guide I've ever read is: Never use a "using namespace" statement globally in a header.

It pollutes the global namespace in the same way that #defines do, which is something that namespaces were designed to avoid.
e.g. this is the problem with defines:#include "windows.h"
#include <algorithm>
int a = 2, b = 4;
int c = std::max( a, b );//compile error - windows contains a #define max line!!!


Now, namespaces solve these kinds of problems for us.
Here is some perfectly valid code:#include <queue>
class queue{};
queue q;//makes my queue, not a std::queue
std::queue<int> q2;//makes a std::queue
Now, if we include a header that has rudely used "using namespace" inside it:#include "Adaline.h" // includes "using namespace std;"
#include <queue>
class queue{};
queue q; // compile error? This code was fine a minute ago?!! thanks Adaline ;)
std::queue<int> q2;


If you really do want to use "using namespace" in a header, then you must at least always wrap it in your own namespace, e.g.//Adaline.h
#include <queue>
namespace adaline
{
using namespace std;//ok, you've only polluted your own namespace
}

Isn't it a bad idea to call a class 'string' anyway ?
The concept extends beyond the [font="Courier New"]std[/font] namespace.
Maybe I'm using two different bits of C++ middleware that both define a Vector3 type? If I using-namespace'd them, I'd get conflicts between the two libraries.

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[quote name='Adaline' timestamp='1313396366' post='4849289']std is used with vector, string,list,etc.... so putting std:: everywhere is not very elegant
A standard C++ rule, that's in almost every C++ style guide I've ever read is: Never use a "using namespace" statement globally in a header.

It pollutes the global namespace in the same way that #defines do, which is something that namespaces were designed to avoid.
e.g. this is the problem with defines:#include "windows.h"
#include <algorithm>
int a = 2, b = 4;
int c = std::max( a, b );//compile error - windows contains a #define max line!!!


Now, namespaces solve these kinds of problems for us.
Here is some perfectly valid code:#include <queue>
class queue{};
queue q;//makes my queue, not a std::queue
std::queue<int> q2;//makes a std::queue
Now, if we include a header that has rudely used "using namespace" inside it:#include "Adaline.h" // includes "using namespace std;"
#include <queue>
class queue{};
queue q; // compile error? This code was fine a minute ago?!! thanks Adaline!
std::queue<int> q2;


If you really do want to use "using namespace" in a header, then you must at least always wrap it in your own namespace, e.g.//Adaline.h
#include <queue>
namespace adaline
{
using namespace std;//ok, you've only polluted your own namespace
};

[/quote]
Thanks for you're explanation (I mean it)
No need to be rude anyway

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