Vectors work when they want to.

This is a discussion on Vectors work when they want to. within the C++ Programming forums, part of the General Programming Boards category; Originally Posted by medievalelks Post the complete piece of code you're trying to compile, not just snippets. And if you're ...

  1. #16
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    Quote Originally Posted by medievalelks View Post
    Post the complete piece of code you're trying to compile, not just snippets. And if you're copy-pasting code, you have to be careful that you don't get any hidden HTML chars in it.
    Code:
    #include <vector>
    #include <iostream>
    std::vector<int> vec;
    vec.push_back(1);
    
    /*
    Errors:
    
    1>(4) : error C2143: syntax error : missing ';' before '.'
    1>(4) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
    1>(4) : error C2371: 'vec' : redefinition; different basic types
    1>        (3) : see declaration of 'vec'
    
    */

  2. #17
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    Ehm.. have you created a function 'int main()' ?

  3. #18
    Its hard... But im here swgh's Avatar
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    This works fine on VC++

    Code:
    #include <iostream>
    #include <vector>
    
    int main()
    {
       std:: vector<int> vec;
    
       vec.push_back(12);
       
       for ( int i = 0; i < vec.size(); i++ )
       {
           std::cout << vec[ i ] << " ";
       }
       
       std::cin.get();
       
       return 0;
    }
    Output is 12 as it should be
    I'm just trying to be a better person - My Name Is Earl

  4. #19
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    Quote Originally Posted by swgh View Post
    This works fine on VC++

    Code:
    #include <iostream>
    #include <vector>
    
    int main()
    {
       std:: vector<int> vec;
    
       vec.push_back(12);
       
       for ( int i = 0; i < vec.size(); i++ )
       {
           std::cout << vec[ i ] << " ";
       }
       
       std::cin.get();
       
       return 0;
    }
    Output is 12 as it should be
    Well the int main made it work, but I've had it where it works without the int main, what is wrong with C++???

    Proof it works without int main:

    Errors, with vectors, windows programming... etc

  5. #20
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    What do you expect your computer to execute when there is no function 'main' ? There is something wrong with your code and your knowledge of C++, not of C++ itself..

  6. #21
    Its hard... But im here swgh's Avatar
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    Every single C.C++ program needs a main function. It is the starting location and the first function called by the operating system. 99&#37; of the time no C++ program will compile without a main function. The OS needs to know where to start from.
    I'm just trying to be a better person - My Name Is Earl

  7. #22
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    Maybe it's not weither it's in the scope or not, but weither the int main is even called.

    Edit: doesn't work tohugh, wtf????

  8. #23
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    Quote Originally Posted by swgh View Post
    Every single C.C++ program needs a main function. It is the starting location and the first function called by the operating system. 99% of the time no C++ program will compile without a main function. The OS needs to know where to start from.
    Even the big programs? Like Firefox?

  9. #24
    Its hard... But im here swgh's Avatar
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    Why are you trying to create a program without main()? Its bad practice anyway, and all good up to date compilers will forbid it unless you have some special setting or circumstance on when main will not be called
    I'm just trying to be a better person - My Name Is Earl

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    You can also just create shared object libraries (.so , Unix/Linux), or dynamic link libraries (.dll , windowz) , which are loaded in some platform or by another program. But then, that program does have a function main.

    No main no brain

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    Quote Originally Posted by swgh View Post
    Why are you trying to create a program without main()? Its bad practice anyway, and all good up to date compilers will forbid it unless you have some special setting or circumstance on when main will not be called
    It's not that, it's just that it seems I get errors when I try to do stuff outside the int main, go check out my other thread about vectors and windows, I have the vector outside the main, and after I fixed it up from the other errors, it worked fine outside the int main, so whats the deal?

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    It could have been defined in the scope of a free function and compiled with -c - i.e., no main() function needed.

    But to the OP, how and when did you expect that code to get executed if it wasn't in main() or any other function?

  13. #28
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    Quote Originally Posted by medievalelks View Post
    It could have been defined in the scope of a free function and compiled with -c - i.e., no main() function needed.

    But to the OP, how and when did you expect that code to get executed if it wasn't in main() or any other function?
    Well I know int main is the main ( -_- ) function that executes it all, but I didn't know it is that strict.

  14. #29
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    The C++ standard has many rules and definitions over main. Main is like the heart of a program. It can ( and somtimes does ) call a single function. But without it, nothing would work. Remember, unless told otherwise by a called function, a program will also terminate via main's return statement.
    I'm just trying to be a better person - My Name Is Earl

  15. #30
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    Quote Originally Posted by swgh View Post
    The C++ standard has many rules and definitions over main. Main is like the heart of a program. It can ( and somtimes does ) call a single function. But without it, nothing would work. Remember, unless told otherwise by a called function, a program will also terminate via main's return statement.
    Okay. So why does the main be an int? why not.. char?

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