Happy Hacking CXX Library (HHXX)

Hackish trinkets and extensions to modern C++

The following three examples should give you a general idea of what HHXX is all about.

A. Universal for_each()

Guess you already know about std::for_each(). It doesn't help when things get high(-dimensional). Following is the best you can do about a three-dimensional object using std::for_each()

for (auto& slice : obj_3d) {
  for (auto& row : slice) {
    std::for_each(std::begin(row), std::end(row), f);
  }
}

With hhxx::for_each(), you can simply

hhxx::for_each(obj_3d, f);

Truth is it works for objects of any dimensions (even scalars!) and of any type supporting range-based for loop!

B. Why should I use hhxx::iswap(x, y) to swap x and y?

Simply speaking, hhxx::iswap(x, y) swaps x and y in the most specialized way possible. It first tries to perform x.swap(y). If the expression turns out to be ill-formed, then tries to perform swap(x, y) with Argument Dependent Lookup (ADL) enabled. If ADL failed, then as a last resort, performs std::swap(x, y). So, stay with hhxx::iswap() and be happy ever since 😸

C. View a one-dimensional linear object as a multi-dimensional one

Have you ever tried to dynamically allocate the storage using a one-dimensional linear object, but access it as if it were a multi-dimensional one? hhxx::make_multi_view() would come to your help. Our mutli view class template provides support for both element access and iterators. It's dynamic, light-weight, with simple syntax. Talk is cheap. Show you the code 😉

int storage[] = { 1, 2, 3, 4, 5, 6, 7, 8 };
// viewed as { {1, 2, 3, 4}, {5, 6, 7, 8} }
auto view2x4 = hhxx::make_multi_view(storage, 2, 4);
assert(view2x4(1, 0) == 5);
// addresses { {1, 2, 3, 4}, {5, 6, 7, 8} }
assert(std::distance(view2x4.begin(), view2x4.end()) == 8);
// addresses {5, 6, 7, 8}
assert(std::distance(view2x4.begin(1), view2x4.end(1)) == 4);
// addresses 3
assert(std::distance(view2x4.begin(0, 2), view2x4.end(0, 2)) == 1);
// viewed as { { {1, 2}, {3, 4} },
//             { {5, 6}, {7, 8} } }
auto view2x2x2 = hhxx::make_multi_view(storage, 2, 2, 2);
// addresses {5, 6}
assert(std::distance(view2x2x2.begin(1, 0), view2x2x2.end(1, 0)) == 2);
...

Feel interested and want to see what else HHXX has to offer? There is a reference manual prepared just for you. So check it out.

Got some nice trinkets yourself? Please do share them with us. We invite you to join the party and play together~ 🎉

• Dependencies
• File Structure
• Build Instructions
• License

Dependencies

• C++14
  • HHXX dances on the cutting edge of modern C++. So, don't expect it to compile nicely on every compiler. If you think it's a problem of the code rather than a compiler or standard library implementation bug, please report an issue.
  • Tested on Apple LLVM version 9.0.0 (clang-900.0.39.2)
  • Tested on gcc 7.3
  • Not yet tested on MSVC. But I'm afraid HHXX won't compile on it. MSVC is a slow child in the compiler family, as people always say.
• Google Test (gtest) for unit tests

File Structure

hhxx/.........library header directory
test/.........unit tests directory
manual.md.....reference manual
README.md
LICENSE
.gitignore

Build Instructions

Currently, HHXX is header-only. Add the directory containing hhxx to your include path and you are ready to go. To build the unit tests, you need to link with gtest (gtest and gtest_main).

License

BSD 3-Clause License