added r_vector named() method (#189)

Co-authored-by: Jim Hester <[email protected]>

Author: sbearrows

NEWS.md

@@ -1,6 +1,7 @@
 # cpp11 (development version)
 
-* Added `x.empty()` method to check if a vector is empty (@sbearrows, #182)
+* New `x.named()` method to check if a vector is named (@sbearrows, #186)
+* New `x.empty()` method to check if a vector is empty (@sbearrows, #182)
 * New `cpp11::na()` function to return the NA sentinals for R objects(@sbearrows, #179)
 * Incorrectly formatted cpp11 decorators now output a more informative error message (@sbearrows, #127)
 * Generated registration code now uses C collation to avoid spurious diffs from `tools::package_native_routine_registration_skeleton()` (@sbearrows, #171)

cpp11test/src/test-list.cpp

@@ -123,7 +123,15 @@ context("list-C++") {
     expect_true(first[1] == 2);
   }
 
-  test_that("empty() works") {
+  test_that("list.named() works") {
+    cpp11::writable::list x({"bar"_nm = 2});
+    expect_true(x.named());
+
+    cpp11::writable::list y(1);
+    expect_false(y.named());
+  }
+  
+  test_that("list.empty() works") {
     cpp11::writable::list x;
 
     expect_true(x.empty());

inst/include/cpp11/r_vector.hpp

@@ -106,6 +106,8 @@ class r_vector {
 
   bool is_altrep() const;
 
+  bool named() const;
+
   R_xlen_t size() const;
 
   operator SEXP() const;
@@ -381,6 +383,11 @@ inline bool r_vector<T>::is_altrep() const {
   return is_altrep_;
 }
 
+template <typename T>
+inline bool r_vector<T>::named() const {
+  return ((this->names()) != R_NilValue);
+}
+
 template <typename T>
 inline R_xlen_t r_vector<T>::size() const {
   return length_;