replaced

replaced_if

replaced_if example

Syntax	Code
Pipe	`rng \| boost::adaptors::replaced_if(pred, new_value)`
Function	`boost::adaptors::replace_if(rng, pred, new_value)`

Precondition:
- The range value_type is convertible to the argument type of pred.
- new_value is convertible to the value_type of the range.
Postconditions: For all elements x in the returned range, the value x is equal to the value of pred(y) ? new_value : y where y is the corresponding element in the original range.
Range Category: Forward Range
Range Return Type: boost::replaced_if_range<typeof(rng)>
Returned Range Category: The range category of rng.

replaced_if example

#include <boost/range/adaptor/replaced_if.hpp>
#include <boost/range/algorithm/copy.hpp>
#include <boost/assign.hpp>
#include <algorithm>
#include <iostream>
#include <vector>

struct is_even
{
    bool operator()(int x) const { return x % 2 == 0; }
};

int main(int argc, const char* argv[])
{
    using namespace boost::adaptors;
    using namespace boost::assign;

    std::vector<int> input;
    input += 1,2,3,4,5,6,7,8,9;

    boost::copy(
        input | replaced_if(is_even(), 10),
        std::ostream_iterator<int>(std::cout, ","));

    return 0;
}

This would produce the output:

1,10,3,10,5,10,7,10,9

Boost C++ Libraries

replaced_if

replaced_if example