A vector of strings
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From: amphetaman on 27 Jun 2008 05:10 I am writing code to put C-style command line arguments (int argc, char *argv[]) into a vector of strings (std::vector<std::string> theArgv). I have a question: Is it better to do a) theArgv.push_back(argv[i]); or b) theArgv.push_back(std::string(argv[i])); or are these identical? -- [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ]
From: Thomas Maeder on 27 Jun 2008 16:27 amphetaman(a)gmail.com writes: > I am writing code to put C-style command line arguments (int argc, > char *argv[]) into a vector of strings (std::vector<std::string> > theArgv). I have a question: Is it better to do > > a) theArgv.push_back(argv[i]); > > or > > b) theArgv.push_back(std::string(argv[i])); > > or are these identical? push_back() takes a T const & (i.e. std::string const &), so whether or not your code explictily converts argv[i] to std::string, this conversion is going to happen. Both versions are thus equivalent. Is there anything wrong with std::vector<std::string> theArgv(argv,argv+argc); , though? -- [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ]
From: peter koch larsen on 27 Jun 2008 16:27
On 27 Jun., 22:10, ampheta...(a)gmail.com wrote: > I am writing code to put C-style command line arguments (int argc, > char *argv[]) into a vector of strings (std::vector<std::string> > theArgv). I have a question: Is it better to do > > a) theArgv.push_back(argv[i]); > > or > > b) theArgv.push_back(std::string(argv[i])); They are identical. Better than the loop would be to use std::copy (from algorithm) with a back_inserter. Look it up and be wiser. /Peter -- [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] |