Hi,
I wish to declare a vector of deque of int, which I do as follows.
#include<vector >
#include<deque>
#include<iostre am>
using namespace std;
int main(int argc, char* argv[])
{
int i=1;
int N=0;
while(i<=argc)
{
// parse arguments
// Most importantly extract the value of N
// as
N=atoi(argv[i]);
i++;
}
// some stuff
//declare a vector of deque of int
// vector contains N deque<int>
// each of which are empty initially
// First attempt
vector<deque<in t> > _MyVariable( N, deque<int>());
// Second Attempt
vector<deque<in t> > _MyVariable2 (N, deque<int>(0));
// some more stuff
return 0;
}
The compiler cribs
"Warning: should not initialize a non-const reference with a
temporary." in the STL code which is instantiated in the lines of
interest above.
Could someone please clarify the exact effects of initializing in the
above fashion ?
which of the above two attempts should I use ? Is it better not to
initialize the deque i.e. to use
vector<deque<in t> > _MyVar (N);
?
Thanks In Advance.
Best Regards,
Madhu. 4 1759
hrmadhu wrote: Hi, I wish to declare a vector of deque of int, which I do as follows.
#include<vector > #include<deque> #include<iostre am> using namespace std;
int main(int argc, char* argv[]) { int i=1; int N=0; while(i<=argc) { // parse arguments // Most importantly extract the value of N // as N=atoi(argv[i]); i++; } // some stuff
//declare a vector of deque of int // vector contains N deque<int> // each of which are empty initially
// First attempt vector<deque<in t> > _MyVariable( N, deque<int>());
You're not allowed (in standard C++) to use that name. At least get rid
of the underscore. // Second Attempt vector<deque<in t> > _MyVariable2 (N, deque<int>(0));
// some more stuff return 0;
You don't need that return statement.
}
The compiler cribs
"Warning: should not initialize a non-const reference with a temporary." in the STL code which is instantiated in the lines of interest above.
Could someone please clarify the exact effects of initializing in the above fashion ? which of the above two attempts should I use ? Is it better not to initialize the deque i.e. to use vector<deque<in t> > _MyVar (N); ?
Yes, IMHO. That's the right way to do it, assuming you change the
variable name.
Good luck,
Jeff
Thanks In Advance. Best Regards, Madhu.
>Jeff Schwab <je******@comca st.net> wrote in message news: // First attempt vector<deque<in t> > _MyVariable( N, deque<int>());
You're not allowed (in standard C++) to use that name. At least get rid of the underscore.
Wow!! I didnt know that. As my coding style, I always prefix all
private and protected members of my classes with _ . Could you please
tell me why and where I can find more on this. // Second Attempt vector<deque<in t> > _MyVariable2 (N, deque<int>(0));
// some more stuff return 0;
You don't need that return statement.
if I do not put this, then the compiler cribs that main, which is
declared int main(...) does not have a return value. Also, isnt that
the way I return whether the program executed with or without errors ?
return 0 suggests that the program ran successfully, while return -1
says there was an error ? }
The compiler cribs
"Warning: should not initialize a non-const reference with a temporary." in the STL code which is instantiated in the lines of interest above.
Could someone please clarify the exact effects of initializing in the above fashion ? which of the above two attempts should I use ? Is it better not to initialize the deque i.e. to use vector<deque<in t> > _MyVar (N); ?
Yes, IMHO. That's the right way to do it, assuming you change the variable name.
if so, can I then simply use the variable as
_MyVar[i].push_back() ?
or do I need to create non-temporary deque<int> and push them back
into the vector one by one ?
Thanks again
Madhu
hrmadhu wrote: Jeff Schwab <je******@comca st.net> wrote in message news:
// First attempt vector<deque<in t> > _MyVariable( N, deque<int>()); You're not allowed (in standard C++) to use that name. At least get rid of the underscore.
Wow!! I didnt know that. As my coding style, I always prefix all private and protected members of my classes with _ . Could you please tell me why and where I can find more on this.
TC++PL, p.81:
Names starting with an underscore are reserved for
special facilities in the implementation and the run-
time environment, so such names should not be used in
application programs. // Second Attempt vector<deque<in t> > _MyVariable2 (N, deque<int>(0));
// some more stuff return 0;
You don't need that return statement.
if I do not put this, then the compiler cribs that main, which is declared int main(...) does not have a return value.
Your compiler is non-standard. In standard C++, the default return
value of main is 0. You are correct to declare it returning an int.
Also, isnt that the way I return whether the program executed with or without errors ? return 0 suggests that the program ran successfully, while return -1 says there was an error ?
That depends on your system. On Unix, you can return whatever you want,
as long as you document it. There is a sort of gentlemen's agreement
that 0 means success. }
The compiler cribs
"Warning: should not initialize a non-const reference with a temporary. " in the STL code which is instantiated in the lines of interest above.
Could someone please clarify the exact effects of initializing in the above fashion ? which of the above two attempts should I use ? Is it better not to initialize the deque i.e. to use vector<deque <int> > _MyVar (N); ?
Yes, IMHO. That's the right way to do it, assuming you change the variable name.
if so, can I then simply use the variable as _MyVar[i].push_back() ?
Assuming you change the variable name, and 0 <= i < N, yes.
or do I need to create non-temporary deque<int> and push them back into the vector one by one ?
No, but you can if you like.
Thanks again Madhu
-Jeff
Thanks Jeff. Got it compiling without any error. (in fact it was also
running without error - but I just dislike compiler warnings!!)
Thanks again.
Best Regards,
Madhu.
Jeff Schwab <je******@comca st.net> wrote in message news:<1K******* *************@c omcast.com>... hrmadhu wrote:Jeff Schwab <je******@comca st.net> wrote in message news:
// First attempt vector<deque<in t> > _MyVariable( N, deque<int>());
You're not allowed (in standard C++) to use that name. At least get rid of the underscore.
Wow!! I didnt know that. As my coding style, I always prefix all private and protected members of my classes with _ . Could you please tell me why and where I can find more on this.
TC++PL, p.81:
Names starting with an underscore are reserved for special facilities in the implementation and the run- time environment, so such names should not be used in application programs.
// Second Attempt vector<deque<in t> > _MyVariable2 (N, deque<int>(0));
// some more stuff return 0;
You don't need that return statement.
if I do not put this, then the compiler cribs that main, which is declared int main(...) does not have a return value.
Your compiler is non-standard. In standard C++, the default return value of main is 0. You are correct to declare it returning an int.
Also, isnt that the way I return whether the program executed with or without errors ? return 0 suggests that the program ran successfully, while return -1 says there was an error ?
That depends on your system. On Unix, you can return whatever you want, as long as you document it. There is a sort of gentlemen's agreement that 0 means success.
}
The compiler cribs
"Warning: should not initialize a non-const reference with a temporary. " in the STL code which is instantiated in the lines of interest above.
Could someone please clarify the exact effects of initializing in the above fashion ? which of the above two attempts should I use ? Is it better not to initialize the deque i.e. to use vector<deque <int> > _MyVar (N); ?
Yes, IMHO. That's the right way to do it, assuming you change the variable name.
if so, can I then simply use the variable as _MyVar[i].push_back() ?
Assuming you change the variable name, and 0 <= i < N, yes.
or do I need to create non-temporary deque<int> and push them back into the vector one by one ?
No, but you can if you like.
Thanks again Madhu
-Jeff This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics |
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