return *this from the free-getter, member-setter property() overload

Author: kevinushey

ChangeLog

@@ -1,3 +1,13 @@
+2026-10-29  Kevin Ushey <kevinushey@gmail.com>
+
+	* inst/include/Rcpp/module/Module_Add_Property.h: Return *this from
+	the property() overload taking a free-function getter and a member
+	function setter, which fell off the end and trapped at module load
+	(#1519)
+	* inst/tinytest/cpp/Module.cpp: Expose one property per property()
+	overload
+	* inst/tinytest/test_module.R: Test them
+
 2026-10-23  Dirk Eddelbuettel  <edd@debian.org>
 
 	* DESCRIPTION (Version, Date): Roll micro version and date

inst/include/Rcpp/module/Module_Add_Property.h

@@ -83,6 +83,7 @@
 			name_,
 			new CppProperty_GetPointer_SetMethod<Class,PROP>(GetMethod, SetMethod, docstring)
 		) ;
+		return *this ;
 	}
 
 	template <typename PROP>

inst/tinytest/cpp/Module.cpp

@@ -89,6 +89,24 @@ class ModuleNum{
     int y;
 };
 
+class ModuleProperties {
+public:
+    ModuleProperties() : value(0.0) {}
+
+    double get() { return value; }
+    double get_const() const { return value; }
+    void set(double value_) { value = value_; }
+
+    double value;
+};
+
+double ModuleProperties_get(ModuleProperties* p) {
+    return p->value;
+}
+void ModuleProperties_set(ModuleProperties* p, double value) {
+    p->value = value;
+}
+
 class ModuleNumber{
 public:
     ModuleNumber() : x(0.0), y(0) {};
@@ -193,6 +211,21 @@ RCPP_MODULE(demoModule) {
         .property("y", &ModuleNum::getY)
         ;
 
+    // one property per class_::property() overload: getters are member,
+    // const member or free functions, setters are member or free functions
+    class_<ModuleProperties>("ModuleProperties")
+        .constructor()
+        .property("get", &ModuleProperties::get)
+        .property("get_const", &ModuleProperties::get_const)
+        .property("get_free", &ModuleProperties_get, "free getter")
+        .property("get_set", &ModuleProperties::get, &ModuleProperties::set)
+        .property("get_const_set", &ModuleProperties::get_const, &ModuleProperties::set)
+        .property("get_set_free", &ModuleProperties::get, &ModuleProperties_set)
+        .property("get_const_set_free", &ModuleProperties::get_const, &ModuleProperties_set)
+        .property("get_free_set", &ModuleProperties_get, &ModuleProperties::set)
+        .property("get_free_set_free", &ModuleProperties_get, &ModuleProperties_set)
+        ;
+
     class_<ModuleNumber>("ModuleNumber")
 
         .constructor()

inst/tinytest/test_module.R

@@ -85,6 +85,27 @@ expect_equal( w$x, 2.0 )
 
 expect_error( { w$y <- 3 } )
 
+## every class_::property() overload; the free getter + member setter one
+## did not return *this, which aborted loading the whole module (#1519)
+p <- new( ModuleProperties )
+p$get_set <- 1.0
+expect_equal( p$get_set, 1.0 )
+p$get_const_set <- 2.0
+expect_equal( p$get_const_set, 2.0 )
+p$get_set_free <- 3.0
+expect_equal( p$get_set_free, 3.0 )
+p$get_const_set_free <- 4.0
+expect_equal( p$get_const_set_free, 4.0 )
+p$get_free_set <- 5.0
+expect_equal( p$get_free_set, 5.0 )
+p$get_free_set_free <- 6.0
+expect_equal( p$get_free_set_free, 6.0 )
+
+expect_equal( c(p$get, p$get_const, p$get_free), c(6.0, 6.0, 6.0) )
+expect_error( { p$get <- 7.0 } )
+expect_error( { p$get_const <- 7.0 } )
+expect_error( { p$get_free <- 7.0 } )
+
 #    test.Module.member <- function(){
 w <- new( ModuleNumber )
 expect_equal( w$x, 0.0 )