added hpx::fill but it only works for 1D vector

Signed-off-by: Dikshant <[email protected]>

hpx-sys/include/wrapper.h

@@ -110,3 +110,15 @@ inline bool hpx_equal(rust::Slice<const int32_t> src, rust::Slice<const int32_t>
         dest.begin(), dest.end()
     );
 }
+
+inline void hpx_fill(rust::Vec<int32_t>& src, int32_t value) {
+    std::vector<int32_t> cpp_vec(src.begin(), src.end());
+
+    hpx::fill(hpx::execution::par, cpp_vec.begin(), cpp_vec.end(), value);
+
+    src.clear();
+    src.reserve(cpp_vec.size());
+    for (const auto& item : cpp_vec) {
+        src.push_back(item);
+    }
+}

hpx-sys/src/lib.rs

@@ -25,6 +25,9 @@ pub mod ffi {
         fn hpx_count_if(vec: &Vec<i32>, pred: fn(i32) -> bool) -> i64;
         fn hpx_ends_with(src: &[i32], dest: &[i32]) -> bool;
         fn hpx_equal(slice1: &[i32], slice2: &[i32]) -> bool;
+
+        // will only work for 1D vectors
+        fn hpx_fill(src: &mut Vec<i32>, value: i32);
     }
 }
 
@@ -286,4 +289,27 @@ mod tests {
             assert_eq!(result, 0);
         }
     }
+
+    #[test]
+    #[serial]
+    fn test_hpx_fill() {
+        let (argc, mut argv) = create_c_args(&["test_hpx_fill"]);
+
+        let hpx_main = |_argc: i32, _argv: *mut *mut c_char| -> i32 {
+            let mut v = vec![0; 10];
+            ffi::hpx_fill(&mut v, 42);
+            assert!(v.iter().all(|&x| x == 42));
+
+            let mut v2 = vec![0; 1_000_000]; // testing on a long vector
+            ffi::hpx_fill(&mut v2, 7);
+            assert!(v2.iter().all(|&x| x == 7));
+
+            ffi::finalize()
+        };
+
+        unsafe {
+            let result = ffi::init(hpx_main, argc, argv.as_mut_ptr());
+            assert_eq!(result, 0);
+        }
+    }
 }