Future exemple works

Examples/future.cpp

-#include <array>
+#include <execution>
+#include <iomanip>
 #include <iostream>
 #include <ranges>
 #include <vector>
@@ -7,22 +8,39 @@
 #include "includes/cartesian_product.hpp"
 #include "includes/mdspan.hpp"
 
-constexpr int dim_x = 5;
-constexpr int dim_y = 5;
+constexpr int dim_x = 8;
+constexpr int dim_y = 8;
 
 int main() {
-    std::array<float, dim_x * dim_y> data{0};
+    std::vector<int> data{dim_x * dim_y};
 
+    auto md = std::mdspan{data.data(), dim_x, dim_y};
+
+    // We create a view for x & y indexes
     auto xs = std::views::iota(0, dim_x);
     auto ys = std::views::iota(0, dim_y);
 
+    // We build the indexes using the cartesian product
     auto idxs = std::views::cartesian_product(xs, ys);
 
-    auto md = std::experimental::mdspan{data.data(), dim_x, dim_y};
-
-    std::for_each(idxs.begin(), idxs.end(), [&md](auto tup) {
-        const auto& [x, y] = tup;
-        std::cout << x << "," << y << std::endl;
+    // We perform our operations on GPU
+    std::for_each(std::execution::par_unseq,
+                  idxs.begin(),
+                  idxs.end(),
+                  // Here we need to do a copy capture so that compiler knows that
+                  // we will use the underlying memory on the GPU.
+                  [md](auto tup) {
+                      const auto& [x, y] = tup;
+                      md(x, y) = x * y;
+                  });
+
+    // We print the result, since it's performed on CPU,
+    // we can simply capture by reference.
+    std::for_each(xs.begin(), xs.end(), [&md, &ys](auto i) {
+        std::for_each(ys.begin(), ys.end(), [&md, i](auto j) {
+            std::cout << std::setw(3) << md(i, j);
+        });
+        std::cout << "\n";
     });
 
     std::cout << "\n";

Examples/makefile

 .PHONY:clean all
 
+CC=nvc++
+FLAGS=--std=c++23 -stdpar=gpu
 INCLUDES_WARNINGS:=--diag_suppress useless_using_declaration
 
+
 all: artefacts/future
 
 artefacts/future: artefacts/future.o
-	nvc++ $^ -o $@
+	$(CC) $(FLAGS) $^ -o $@
 
 artefacts/%.o: %.cpp
-	nvc++ --std=c++23 $(INCLUDES_WARNINGS) -c $^ -o $@
+	$(CC) $(FLAGS) $(INCLUDES_WARNINGS) -c $^ -o $@
 
 clean:
 	rm -vf artefacts/**
\ No newline at end of file