Filtering `iter::product` about cppitertools HOT 3 CLOSED

This looks like a constness issue with range::Iterator::operator*(); (not
being marked const of course). For this limited case it might work just as
well to make the range operator* a const member, but that doesn't
generalize well. This hints at a bigger issue I suspected would need
addressing eventually. It seems that time has come today!

On Tue, Sep 23, 2014 at 3:13 AM, iliocatallo [email protected]
wrote:

Hi,

with respect to #16
#16, I was trying to
filter out the upper right corner of the matrix using iter::filter.
Here's the showcase code:

int main() {

auto range = iter::product(iter::range(10), iter::range(5));

for (auto&& ij: iter::filter([](std::tuple<unsigned, unsigned> const& c) {return std::get<0>(c) >= std::get<1>(c);}, range))
    std::cout << std::get<0>(ij) << "," << std::get<1>(ij) << std::endl;

Unfortunately, this does not compile. Clang reads:

error: indirection requires pointer operand ('const iterator_typeiter::Productor<iter::Range<int, iter::Range > &>' (aka 'const iter::Productoriter::Range<int, iter::Range >::Iterator') invalid)
return *this->sub_iter;

Same error if I replace iter::filter with boost::adaptors::filtered, so I
presume the error should be in iter::Producter.

Thanks.

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#17.

from cppitertools.

nevermind. this is gonna run deeper than expected.

from cppitertools.

fixed with d043887

from cppitertools.