StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

POLooped push_back against resize() + iterator
text
Body
copied!<p>Simple question; what's better and why?</p> <pre><code> out.resize( in.size() ); T1::iterator outit = out.begin(); for( inIt = in.begin() to end, ++inIt, ++outIt ) *outit = *inIt OR out.erase(); for( inIt = in.begin() to end, ++inIt ) out.push_back( inIt ); </code></pre> <p>I'm assuming the memory assignment implicit in push_back is worth avoiding but want to make sure.</p> <p>Thanks</p> <p>EDIT: Thanks for the out = in suggestions guys ;). The actual code I'm playing with is:</p> <pre><code> template//can't stop the browser ignoring th class T1, class T2 in angle brackets bool asciihex( T1& out, const T2& in ) { //out.erase(); out.resize( in.size() / 2 ); if( std::distance( in.begin(), in.end() ) % 2 )//use distance rather than size to minimise the requirements on T2? return false; for( T2::const_iterator it = in.begin(); it != in.end(); it += 2 ) { out.push_back(((( (*it > '9' ? *it - 0x07 : *it) - 0x30) '9' ? *(it+1) - 0x07 : *(it+1)) - 0x30) & 0x000f)); } return true; } template bool asciihex( T1& out, const T2& in ) { size_t size = in.size(); if( size % 2 )//use distance rather than size to minimise the requirements on T2? return false; out.resize( size / 2 ); T1::iterator outit = out.begin(); for( T2::const_iterator it = in.begin(); it != in.end(); it += 2, ++outit ) { *outit = ((( (*it > '9' ? *it - 0x07 : *it) - 0x30) '9' ? *(it+1) - 0x07 : *(it+1)) - 0x30) & 0x000f); } return true; } </code></pre> <p>Edit: I've marked push_back as the answer as it seems to be the consensus and, therefore, more useful to anyone else with the same problem. However I have ended up using the iterator method as one of the container classes I'm interested in doesn't support push_back... mileage varies.</p>

Querying!

Guidance

An individual column

Larger individual text columns get their own page to allow for proper reading.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload