C++ ostream_iterator creation throws exception

Question

Okay, I have the following vector:

std::vector< std::pair<std::shared_ptr<std::fstream>, uint32_t> > writer = {
    { std::make_shared<std::fstream>("file1.csv", std::fstream::out | std::fstream::trunc), bin_c1 },
    { std::make_shared<std::fstream>("file2.csv", std::fstream::out | std::fstream::trunc), bin_c1 },
    { std::make_shared<std::fstream>("file3.csv", std::fstream::out | std::fstream::trunc), bin_c2 },
    { std::make_shared<std::fstream>("file4.csv", std::fstream::out | std::fstream::trunc), bin_c2 },
    { std::make_shared<std::fstream>("file5.csv", std::fstream::out | std::fstream::trunc), bin_c3 },
    { std::make_shared<std::fstream>("file6.csv", std::fstream::out | std::fstream::trunc), bin_c3 }
};

and then I have the following code:

for_each_idx(this->data.begin(), this->data.end(), 0, [&writer](unsigned index, std::vector<float> value) {
     auto it_start  = value.begin();
     auto it_end    = value.begin() + std::min(value.size(), writer.at(index).second);
     auto it_stream = std::ostream_iterator<float>(*writer.at(index).first << std::fixed, ",");

     std::transform(it_start, it_end, it_stream, [](float num){ /* Do stuff */ });
});

The problem is at this line:

auto it_stream = std::ostream_iterator<float>(*writer.at(index).first << std::fixed, ",");

which gives me an access violation error. At first I thought it was the .at(index) but index's value is correct and yes writer and this->data vectors have the same size. So, what am I missing?

EDIT: Okay I found a way to make it work. I changed the writer creation:

std::vector< std::pair<std::shared_ptr<std::fstream>, uint32_t> > writer;

writer.push_back({ std::make_shared<std::fstream>("file1.csv", std::fstream::out | std::fstream::trunc), bin_c1 });
writer.push_back({ std::make_shared<std::fstream>("file2.csv", std::fstream::out | std::fstream::trunc), bin_c1 });
writer.push_back({ std::make_shared<std::fstream>("file3.csv", std::fstream::out | std::fstream::trunc), bin_c2 });
writer.push_back({ std::make_shared<std::fstream>("file4.csv", std::fstream::out | std::fstream::trunc), bin_c2 });
writer.push_back({ std::make_shared<std::fstream>("file5.csv", std::fstream::out | std::fstream::trunc), bin_c3 });
writer.push_back({ std::make_shared<std::fstream>("file6.csv", std::fstream::out | std::fstream::trunc), bin_c3 });

Still, can someone explain why this works and when I create the writer using the initializer list it actually treats every shared_ptr as uninitialized pointer?

EDIT: Installing Visual Studio 2013 Update 5 solved the problem.