Re: std::string::assign range

On 3/6/2015 2:19 AM, Juha Nieminen wrote:


Just that I don't know it, but that looks to be better.
So, taking your suggestions in combination with Victor's, here is my
current listing:

// Shared Includes
#include "Exception.h"
#include "PerformanceTimer.h"

// Standard Includes
#include <iostream>
#include <fstream>
#include <sstream>
#include <string>
#include <vector>
#include <cstdio>

const unsigned int NUM_ITERATIONS = 100;

//--------------------------------------------------------------------------------------------------

void Method1()
{
     std::ifstream file("test.txt");
     if( !file )
     {
         // Error
         throw Shared::Exception(__FILE__, __LINE__, "Cannot open test
file");
     }

     std::string textToParse(std::istream_iterator<char>(file),
                             std::istream_iterator<char>());

     file.close();
}

//--------------------------------------------------------------------------------------------------

void Method2()
{
     std::ifstream file("test.txt");
     if( !file )
     {
         // Error
         throw Shared::Exception(__FILE__, __LINE__, "Cannot open test
file");
     }

     std::string textToParse;

     file >> std::noskipws;
     std::copy(std::istream_iterator<char>(file),
               std::istream_iterator<char>(),
               std::inserter(textToParse, textToParse.begin()));

     file.close();
}

//--------------------------------------------------------------------------------------------------

void Method3()
{
     std::ifstream file("test.txt");
     if( !file )
     {
         // Error
         throw Shared::Exception(__FILE__, __LINE__, "Cannot open test
file");
     }

     std::stringstream textToParse;
     textToParse << file.rdbuf();

     file.close();
}

//--------------------------------------------------------------------------------------------------

int main()
{
     Method1();
     Method2();
     Method3();

     Shared::PerformanceTimer timer;
     for(unsigned count = 0; count < NUM_ITERATIONS; ++count)
     {
         Method1();
     }
     std::cout << "Method 1 :" << timer.Stop() << std::endl;

     timer.Start();
     for(unsigned count = 0; count < NUM_ITERATIONS; ++count)
     {
         Method2();
     }
     std::cout << "Method 2 :" << timer.Stop() << std::endl;

     timer.Start();
     for(unsigned count = 0; count < NUM_ITERATIONS; ++count)
     {
         Method3();
     }
     std::cout << "Method 3 :" << timer.Stop() << std::endl;
}

and the output is:
Method 1 :0.012716
Method 2 :0.361421
Method 3 :0.141371