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   comp.lang.c++.moderated      Moderated discussion of C++ superhackery      33,346 messages   

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   Message 31,596 of 33,346   
   =?ISO-8859-1?Q?Daniel_Kr=FCgler?= to topoden   
   Re: "for_each + lambda" vs "ranged for"   
   01 Nov 11 05:39:39   
   
   6531c631   
   From: daniel.kruegler@googlemail.com   
      
   On 2011-11-01 11:58, topoden wrote:   
   > Hi,   
   >   
   > Given we now have ranged for loops... Why do we still need   
   > std::for_each + lambda? Doesn't ranged for loop do exactly the same   
   > now?   
   >   
   > for (auto e : range)   
   > {   
   >      // do something   
   > }   
   >   
   > vs   
   >   
   > std::for_each(begin(range), end(range), [=] (auto e)   
   > {   
   >      // do something   
   > });   
      
   The for-range loop is no proper replacement in all cases. Many iterators   
   in the library are created by factory functions or constructors, e.g.   
   consider   
      
   std::regex re = ...;   
   std::string s = ...;   
   std::for_each(std::sregex_iterator{s.begin(), s.end(), re},   
      std::sregex_iterator{}, [](const std::smatch&) { ...; }   
   );   
      
   HTH & Greetings from Bremen,   
      
   Daniel Krügler   
      
      
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