Applications through C++

Hello C++ lovers, today am going to make you all familiar with some useful trade offs / applications of C++. These applications are

You can simply implement all these functionalities through these methods:

Concurrent Waiting

Concurrent waiting can be drawn on the basis of these three mechanisms

Concurrent Waiting | .get

size_t

file_sizes( string file1, string file2 )

   {

   task<file> f1 = open(file1),

              f2 = open(file2);

   return f1.get().size() +

          f2.get().size();

}

Concurrent Waiting | .then

task<size_t>

file_sizes( string file1, string file2 )

    {

   task<file> f1 = open(file1),

              f2 = open(file2);

   return when_all(f1,f2)

      .then([=](tuple<file,file> fs)

       {

         return get<1>(fs).size() +

                get<2>(fs).size();

      });

}

Concurrent Waiting | .then + await

task<size_t>

file_sizes( string file1, string file2 ) __async

    {

   task<file> f1 = open(file1),

              f2 = open(file2);

   return (__await f1).size() +

          (__await f2).size();

}

Real Payoffs | Branches & Loops

Branches & Loops | .get

string

read( string file, string suffix )

   {

   istream fi = open(file).get();

   string ret, chunk;

   while( (chunk = fi.read().get()).size() )

      ret += chunk + suffix;

   return ret;

}

Branches & Loops | .then

task<string>

read( string file, string suffix )

  {

   return open(file)

   .then([=](istream fi)

     {

      auto ret = make_shared<string>();

      auto next =

         make_shared<function<task<string>()>>(

      [=]

     {

         fi.read()

         .then([=](string chunk)

                {

            if( chunk.size() )

                 {

               *ret += chunk + suffix;

               return (*next)();

            }

            return *ret;

         });

      });

      return (*next)();

   });

}

Branches & Loops | .then + await

task<string>

read( string file, string suffix ) __async

{

   istream fi = __await open(file);

   string ret, chunk;

   while( (chunk = __await fi.read()).size() )

      ret += chunk + suffix;

   return ret;

}