Re: [boost] BOOST_FOREACH slow?

Sorry, I have forgotten to write that I use VS2005 and i compile with the macro _SECURE_SCL=0 defined.. Best regards Hansjörg Hansi schrieb:

Hello,

I have made a few tests with the performance of BOOST_FOREACH. The results are for me unexpected slow...may be one has an idea if I make something wrong...

vector[int]: index:0.00167619 vector[int]: iterator:0.00167619 vector[int]: BOOST_FOREACH:9.40036

list[int]: iterator:239.669 list[int]: BOOST_FOREACH:233.219

vector[TestData]: index:0.00167619 vector[TestData]: iterator:0.00167619 vector[TestData]: BOOST_FOREACH:9.40008

list[TestData]: iterator:233.827 list[TestData]: BOOST_FOREACH:238.513

testArray[int]: index:0.00167619 testArray[int]: BOOST_FOREACH:9.40008

Best regards Hansjörg

the test program was:

// ForEach.cpp : Defines the entry point for the console application. //

#include "stdafx.h" #include "..\include\PerformanceCounter.h" #include <vector> #include <boost\foreach.hpp> #include <iostream> #include <list>

using namespace std; using namespace Microtec;

class TestData { public: TestData(int val1, int val2, int val3):var1(val1),var2(val2),var3(val3){} int var1; int var2; int var3; };

int testArray[10000000];

int _tmain(int argc, _TCHAR* argv[]) { vector<int> data; list<int> lstData; vector<TestData> vectorTestData; list<TestData> lstTestData;

for(int i = 0; i < 10000000;i++) { data.push_back(i); lstData.push_back(i); vectorTestData.push_back(TestData(i,i,i)); lstTestData.push_back(TestData(i,i,i)); }

int res = 0;

const int actSize = (int)data.size(); for(int i = 0; i < actSize; i++) { res += data[i]; } //takes 0.0017 ms

res = 0; for(vector<int>::iterator it = data.begin(); it != data.end(); it++) { res += *it; } //takes 0.0017 ms

res = 0; BOOST_FOREACH(int val,data) { res += val; } //takes 9.400 ms

//list res = 0; for(list<int>::iterator it = lstData.begin(); it != lstData.end(); it++) { res += *it; } //takes 239.669 ms

res = 0; BOOST_FOREACH(int val,lstData) { res += val; } //takes 233.219 ms

//vector TestData for(int i = 0; i < actSize; i++) { res += vectorTestData[i].var1; } //takes 0.0017 ms

res = 0; for(vector<TestData>::iterator it = vectorTestData.begin(); it != vectorTestData.end(); it++) { res += it->var1; } //takes 0.0017 ms

res = 0; BOOST_FOREACH(TestData& val,vectorTestData) { res += val.var1; } //takes 9.400 ms

//list res = 0; for(list<TestData>::iterator it = lstTestData.begin(); it != lstTestData.end(); it++) { res += it->var1; } //takes 233.827 ms

res = 0; BOOST_FOREACH(TestData& val,lstTestData) { res += val.var1; } //takes 238.827 ms

for(int i = 0; i < actSize; i++) { res += testArray[i]; } //takes 0.0017 ms

res = 0; BOOST_FOREACH(int val,testArray) { res += val; } //takes 9.400 ms

return 0; }

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