Warning

This part is alpha: work in progress. May change at any time.

Using basic concepts

make_immutable_array

Synopsis:

template<typename Expr, int ... ph> auto make_immutable_array(Expr const &, clef::pair<ph,range> ...);  (1)
template<typename Function>         auto make_immutable_array(Function, range ...);                     (2)

• (1) From a clef expression, and a range for each placeholder in the expression, build a lazy object modelling ImmutableCuboidArray concept, with the domain built from the ranges:

  Parameters are :

  • expr The lazy expression
  • i_=R : i_ is a placeholder, R a range. The i_=R produce a clef::pair of i_ and R , which is the parameter.

• (2) From a function object and a set of range, build a lazy object modelling ImmutableCuboidArray concept, with the domain built from the ranges:

Example:

#include <triqs/arrays.hpp>
#include <triqs/arrays/make_immutable_array.hpp>
using namespace triqs::arrays;
using triqs::clef::placeholder;
int main() {
  placeholder<0> i_;
  placeholder<1> j_;

  auto a = make_immutable_array(1.0 / (2 + i_ + j_), i_ = range(0, 2), j_ = range(0, 2));

  std::cout << "a = " << a << std::endl;
  std::cout << "a = " << array<double, 2>(a) << std::endl;

  // or if you prefer using a lambda...
  auto b = make_immutable_array([](int i, int j) { return i - j; }, range(0, 2), range(0, 2));

  std::cout << "b = " << b << std::endl;
  std::cout << "b = " << array<double, 2>(b) << std::endl;
}