How to use Delphi's anonymous methods and generics in your C++Builder XE8 applications

Posted by on in Tips, Tricks and Techniques

With the release of C++Builder XE8 and RAD Studio XE8, we have made it even easier for C++ developers to work wth Delphi's anonymous methods and generics. We have updated the recommended way to handle Delphi anonymous methods in your C++ applications. The revised description, in How to Handle Delphi Anonymous Methods in C++, uses either a Functor (function object) or a Lambda expression. See the code examples on the following RAD Studio XE8 DocWiki pages.

You can also use a lambda wherever an API expects an anonymous method. The DelphiInterface class has been updated to auto-convert to a lambda. This feature can only be used with the Clang-based C++ Compilers. The following example C++ code illustrates use of a lambda.

#include <System.hpp>
#include <System.IOUtils.hpp>
#include <iostream>
int main()
  String ext(".cpp");                   
  TStringDynArray files = TDirectory::GetFiles(TDirectory::GetCurrentDirectory(),
                          [ext](const String Path, const System::Sysutils::TSearchRec &SearchRec) -> bool
                            return ExtractFileExt(SearchRec.Name) == ext;
  std::cout << "Found " << files.Length 
            << " files with ext: '" << AnsiString(ext).c_str() << "'\n";
  for (int i=0; i<files.Length; ++i)
    std::cout << AnsiString(files[i]).c_str() << std::endl;


Tags: C++ C++11 Lambda

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