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POstd::stringstream does not name a type (Global)
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copied!<p>I'm doing a simulation of a few Ising models (lattice with 1 or -1) and I don't want to use files (don't gonna get into details here, I guess :D). So, the thing is, I'm using stringstreams to format the data & data's filename to then separate them with bash. Show you an example code</p> <pre><code>#include <stdio.h> #include <stdlib.h> #include <string.h> #include <iostream> #include <sstream> #include <string> using namespace std; void print2bash(string file, string data); int main(int argc, char *argv[]){ int i, j, n = atoi(argv[1]); // I want to put this outside main() { stringstream ssbash; ssbash.clear(); ssbash.str(""); stringstream ssfile; ssfile.clear(); ssfile.str(""); //} // So I don't have to do ss.clear and ss.str("") every time before using them ssfile << "this_" << n << "_is_the_filename.dat" << endl; for(i = 0; i < n ; i++){ for(j = 0; j < n; j++) ssbash << i*n+j << "\t"; ssbash << endl; } print2bash( ssfile.str(), ssbash.str() ); return 0; } // print2bash(); prints string data; to string file; // This will be used to separate data // afterwards ( i.e. ./Ising.o <arguments> | bash ) void print2bash(string file, string data){ stringstream ssbash; ssbash.clear(); ssbash.str(data); stringstream output; output.clear(); output.str(""); string line; output << "for((i=0;i<1;i++)) do "<< endl; // Buffer all to bash at once while( getline(ssbash,line) ) output << " echo \"" << line << "\";" << endl; output << "done >> " << file; // Appending cout << output.str() << endl; ssbash.clear(); ssbash.str(""); return ; } </code></pre> <p>A regular output of this "sstreams.o" program would be</p> <pre><code>~work/Ising$ ./sstreams.o 5 for((i=0;i<1;i++)) do echo "0 1 2 3 4 "; echo "5 6 7 8 9 "; echo "10 11 12 13 14 "; echo "15 16 17 18 19 "; echo "20 21 22 23 24 "; done >> this_5_is_the_filename.dat </code></pre> <p>You get the idea right? From this thinking flow, what I actually write is <code>./sstreams.o 10 | bash</code> so one gets nicely separated files. But the problem is:</p> <p><strong>I'm getting tired of writing this lines</strong> each time I want to use print2bash() (oh the irony!)</p> <pre><code>stringstream ssbash; ssbash.clear(); ssbash.str(""); stringstream ssfile; ssfile.clear(); ssfile.str(""); </code></pre> <p>Because of that, I want to put the <code>ss</code> as global variables (don't know if this is that kind of awful so the compiler doesn't let me to do it: I'm just a Physicist). So, even if I write <code>std::stringstream</code> for the ss variables after the <code>#include</code>s (and <code>using namespace std</code>), I still get the error</p> <pre><code>error: ‘ssbash’ does not name a type error: ‘ssbash’ does not name a type error: ‘ssfile’ does not name a type error: ‘ssfile’ does not name a type </code></pre> <p>from the compiler. Hope you can help meee.</p> <hr> <p>EDIT: <strong>[SOLVED]</strong></p> <p>The problem was that if I wanted to declare a <code>stringstream</code> out of <code>main()</code> it failed because of the members <code>clear</code> & <code>str</code> where out of context so they can't be used. Besides that, this use was unnecessary because <code>stringstream</code>s are created with empty contents, as @jpalecek and @umlaeute pointed out. </p> <p>I've declared the <code>stringstream</code>s out of main and include a <code>clear()</code> + <code>str("")</code> on <code>print2bash()</code> to give the desired result:</p> <pre><code>#include <stdio.h> #include <stdlib.h> #include <string.h> #include <iostream> #include <sstream> #include <string> #include <vector> using namespace std; stringstream ssbash, ssfile; void print2bash(string file, string data); int main(int argc, char *argv[]){ int i, j, n = atoi(argv[1]), p, np = atoi(argv[2]); vector< vector<int> > chain; chain.resize(n*n); for( p = 0; p < np; p++){ ssfile << "chain_p="<< p << "_filename.dat" << endl; for(i = 0; i < n ; i++){ for(j = 0; j < n; j++){ chain[p].push_back( i*n + j ); ssbash << i*n+j << "\t"; } ssbash << endl; } print2bash( ssfile.str(), ssbash.str() ); } return 0; } void print2bash(string file, string data){ ssbash.str(data); stringstream output; string line; output << "for((i=0;i<1;i++)) do "<< endl; // Buffer all to bash at once while( getline(ssbash,line) ) output << " echo \"" << line << "\";" << endl; output << "done >> " << file; // Appending cout << output.str() << endl; ssfile.clear(); ssfile.str(""); ssbash.clear(); ssbash.str(""); return ; } </code></pre> <p>a regular output of <code>./sstreams.o</code></p> <pre><code>~/work/Ising$ ./sstreams.o 4 2 for((i=0;i<1;i++)) do echo "0 1 2 3 "; echo "4 5 6 7 "; echo "8 9 10 11 "; echo "12 13 14 15 "; done >> chain_p=0_filename.dat for((i=0;i<1;i++)) do echo "0 1 2 3 "; echo "4 5 6 7 "; echo "8 9 10 11 "; echo "12 13 14 15 "; done >> chain_p=1_filename.dat </code></pre> <p>Thanks for everything</p>

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