replace_if


Category: algorithms 
Component type: function 
Prototype
template <class ForwardIterator, class Predicate, class T>
void replace_if(ForwardIterator first, ForwardIterator last, Predicate pred
const T& new_value)
Description
Replace_if replaces every element in the range [first, last) for
which pred returns true with new_value. That is: for every
iterator i, if pred(*i) is true then it performs the assignment *i
= new_value.
Definition
Defined in the standard header algorithm, and in the nonstandard
backwardcompatibility header algo.h.
Requirements on types

ForwardIterator is a model of Forward Iterator.

ForwardIterator is mutable.

Predicate is a model of Predicate.

ForwardIterator's value type is convertible to Predicate's
argument type.

T is convertible to Forward Iterator's value type.

T is Assignable.
Preconditions

[first, last) is a valid range.
Complexity
Linear. Replace_if performs exactly last  first applications of
pred, and at most last  first assignments.
Example
Replace every negative number with 0.
vector<int> V;
V.push_back(1);
V.push_back(3);
V.push_back(2);
V.push_back(1);
replace_if(V.begin(), V.end(), bind2nd(less<int>(), 0), 0);
assert(V[1] == 0 && V[3] == 0);
Notes
See also
replace, replace_copy, replace_copy_if
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