cpptricks

Collection of C++ snippets and header files that could be useful. Build and test with:

cmake .
make test
./test

Description

• invsqrt.h. Quake fast inverse square root for floats/doubles.
• stl_eigen_facade.h. Access vector of structures as Eigen objects
• pairwise_iterator.h. Generates an iterable object pointing to all unique pairs in one container or between two containers. Dereferencing returns a std::tuple holding (const) references to the underlying data.

  std::vector<std::string> v = {"one","two", "three"};
  for (auto [i,j] : internal_pairs(v)):
  std::cout << i << "-" << j << " "; // --> "one-two" "one-three" "two-three"

  (similar to Python's itertools.combinations)

  std::vector<std::string> v1 = {"one","two"}, v2 = {"three"};
  for (auto [i,j] : cartesian_product(v1,v2)):
     std::cout << i << "-" << j << " "; // --> "one-three" "two-three"

  (similar to range-v3's cartesian_product)