Thanks how can I call a function with 2 more parameters, like this: How can I pass 'param1', 'param2' to the fuction doStuff? void A::aFunction( float param1, float param2) { vector<int> aVector; aVector.push_back(1); aVector.push_back(2); aVector.push_back(3); aVector.push_back(4); // want to loop thru the list and call A::print(int i, float param1, float param2)? } void A::doStuff(int i, float param1, float param2) { } On 2/14/06, Noel Yap wrote:

boost::bind isn't necessary for this.

std::copy( aVector.begin(), aVector.end(), std::ostream_iterator< std::string >(std::cout, "\n"));

If you really want to use boost::bind, it would be something like:

std::for_each( aVector.begin(), aVector.end(), boost::bind( &A::print, _1 ) );

although I haven't tried it out myself.

On 2/14/06, Meryl Silverburgh wrote:

...

I have a int vector, and I would like to loop thru the vector and call a function which takes an int (in this case, I want to print).

t void A::aFunction() {

vector<int> aVector; aVector.push_back(1); aVector.push_back(2); aVector.push_back(3); aVector.push_back(4);

// want to loop thru the list and call A::print(int i)? }

void A::print(int i) {

}

how can I do that using boost bind library?

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In Stroustrup's book "The C++ Programming Language -- 3rd edition", 18.6 is "Modifying Sequence Algorithms". 18.6.1 is "Copy". He talks about what is in the standard and then gives an example almost what you are asking for. You could also use the standard Copy (described in 25.2.1 of the standard) and compute the "InputInterator last" using your criterial before doing the copy. Yes, that does make two passes but any test inside the copy loop will cost almost the same. On Feb 15, 2006, at 8:58 PM, yinglcs2@yahoo.com wrote:

How can I copy elements from one STL container to another STL container if a condition is met and if it find an element fails that condition, it stops the copying?

I wonder if Boost has library for that. I don't think the original STL algorithm handle this case.

Thank you.

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Thanks. One more question, why the function 'doStuff' has to be 'public' otherwise, it won't compile? In my example, aFunction is a member function of 'A', so I can put 'doStuff' as private, right? but that won't compile.

for_each( aVector.begin(), aVector.end(), bind( &A::doStuff, this, _1, param1, param2 ) );

Can someone please tell me why? On 2/16/06, Peter Dimov wrote:

Meryl Silverburgh wrote:

...

Thanks how can I call a function with 2 more parameters, like this: How can I pass 'param1', 'param2' to the fuction doStuff?

void A::aFunction( float param1, float param2) {

vector<int> aVector; aVector.push_back(1); aVector.push_back(2); aVector.push_back(3); aVector.push_back(4);

// want to loop thru the list and call A::print(int i, float param1, float param2)?

for_each( aVector.begin(), aVector.end(), bind( &A::doStuff, this, _1, param1, param2 ) );

...

}

void A::doStuff(int i, float param1, float param2) {

}

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Rearranged reply: Meryl Silverburgh wrote:

...

Meryl Silverburgh wrote:

...

Thanks how can I call a function with 2 more parameters, like this: How can I pass 'param1', 'param2' to the fuction doStuff?

void A::aFunction( float param1, float param2) {

vector<int> aVector; aVector.push_back(1); aVector.push_back(2); aVector.push_back(3); aVector.push_back(4);

// want to loop thru the list and call A::print(int i, float param1, float param2)?

for_each( aVector.begin(), aVector.end(), bind( &A::doStuff, this, _1, param1, param2 ) );

...

}

void A::doStuff(int i, float param1, float param2) {

} Thanks. One more question, why the function 'doStuff' has to be 'public' otherwise, it won't compile? In my example, aFunction is a member function of 'A', so I can put 'doStuff' as private, right? but

On 2/16/06, Peter Dimov wrote: that won't compile.

...

for_each( aVector.begin(), aVector.end(), bind( &A::doStuff, this, _1, param1, param2 ) );

Can someone please tell me why?

Not sure what your exactly asking here. for_each is expecting to call a function f( value_type& ), where in this case value type is an int. for_each call this function f for each derefrenced iterator in the sequence v.begin() to v.end(). The bind call above returns such a function, mapping the int in f, to the placeholder in the call to A::doStuff. The assumption is made that A is a class rather than a name space, since you didn't post a complete example. So that makes A::doStuff a member function. Member functions take a this pointer as their hidden 1st argument. A::aFunction is assumed to be a member function as well so the this pointer is available. bind( &A::doStuff // an A member function , this // this instance of A's this pointer , _1 // the derefenced vector::iterator (an int ) , param1 // the 1st float arg value , param2 // the 2nd float arg value ) Jeff Flinn

On 2/15/06, Stuart Dootson wrote:

On 2/14/06, Meryl Silverburgh wrote:

...

I have a int vector, and I would like to loop thru the vector and call a function which takes an int (in this case, I want to print).

void A::aFunction() {

vector<int> aVector; aVector.push_back(1); aVector.push_back(2); aVector.push_back(3); aVector.push_back(4);

// want to loop thru the list and call A::print(int i)? }

void A::print(int i) {

}

how can I do that using boost bind library?

Easiest way is

A anA; std::for_each(aVector.begin(), aVector.end(), boost::bind(&A::print, &anA, _1));

HTH Stuart Dootson

Use 'this' if you're doing the loop in A::aFunction... Stuart