New tricks in C++11 that you have found?

  What are some new fancy tricks that you have found with C++11?
Perhaps something that was either just outright impossible with C++98
or much more difficult/laborious. (And naturally I'm not just talking
about things like "being able to write 'auto' instead of a long type
name", but less obvious tricks.)

  Here are a couple to start off:

  1) In C++98 it's not possible to get a compile-time constant that's
eg. the sum of the elements of an array, even if that array is const.
In C++11 it is now possible by using the new constexpr keyword.

  Example C++11 code:

//---------------------------------------------------------------
#include <iostream>

namespace
{
    constexpr unsigned kSizes[] = { 5, 15, 8, 4, 28, 3, 5, 17 };
    const unsigned kSizesAmount = sizeof(kSizes) / sizeof(kSizes[0]);

    template<unsigned index>
    struct SizesTotal
    {
        constexpr static unsigned value()
        { return kSizes[index] + SizesTotal<index-1>::value(); }
    };

    template<>
    struct SizesTotal<0U>
    {
        constexpr static unsigned value()
        { return kSizes[0]; }
    };

    constexpr unsigned getSizesTotal()
    { return SizesTotal<kSizesAmount - 1>::value(); }
}

int main()
{
    // This is impossible in C++98:
    unsigned values[getSizesTotal()];

    std::cout << "'values' has " << sizeof(values)/sizeof(values[0])
              << " elements\n";
}
//---------------------------------------------------------------

  2) Initializer lists and ranged loops. Technically speaking this is
possible to do in C++98, but it's more laborious:

//---------------------------------------------------------------
#include <iostream>
#include <vector>

void print(int t)
{
    std::cout << t << ", ";
}

template<typename T>
void print(const T &t)
{
    for(auto& i: t) print(i);
    std::cout << '\n';
}

int main()
{
    auto t1 = { 1, 2, 3, 4, 5, 6, 7, 8, 9 };
    std::cout << "--- t1:\n";
    print(t1);

    std::vector<std::vector<int>> t2[] =
    { { { 1, 2 }, { 3, 4 }, { 5, 6 } },
      { { 11, 12, 13 }, { 14, 15 } },
      { { 21 }, { 22, 23, 24, 25, 26 }, { 27, 28, 29 } },
      { { 31, 32, 33, 34, 35, 36, 37 } },
      { { 41 }, { 42 } }
    };
    std::cout << "--- t2:\n";
    print(t2);
}
//---------------------------------------------------------------