improve dynamic loading example

Author: jll63

doc/modules/ROOT/examples/shared_libs/CMakeLists.txt

@@ -8,7 +8,7 @@ message(STATUS "Building dynamic_shared loading examples")
 # ------------------------------------------------------------------------------
 # static linking
 
-add_library(shared SHARED overriders.cpp tiger.cpp)
+add_library(shared SHARED extensions.cpp)
 target_link_libraries(shared Boost::openmethod)
 set_target_properties(shared PROPERTIES ENABLE_EXPORTS ON)
 
@@ -28,7 +28,7 @@ add_test(NAME dynamic_shared COMMAND dynamic)
 # ------------------------------------------------------------------------------
 # dynamic loading, indirect virtual_ptrs
 
-add_library(indirect_shared SHARED indirect_overriders.cpp indirect_tiger.cpp)
+add_library(indirect_shared SHARED indirect_extensions.cpp)
 target_compile_definitions(
     indirect_shared PUBLIC BOOST_OPENMETHOD_DEFAULT_REGISTRY=indirect_registry)
 target_link_libraries(indirect_shared Boost::openmethod Boost::dll)

doc/modules/ROOT/examples/shared_libs/animals.hpp

@@ -10,6 +10,7 @@
 
 // tag::content[]
 // animals.hpp
+
 #include <string>
 #include <boost/openmethod.hpp>
 
@@ -22,7 +23,6 @@ BOOST_OPENMETHOD(
         boost::openmethod::virtual_ptr<Animal>,
         boost::openmethod::virtual_ptr<Animal>),
     std::string);
-
 // end::content[]
 
 #endif

doc/modules/ROOT/examples/shared_libs/dynamic_main.cpp

@@ -3,20 +3,25 @@
 // accompanying file LICENSE_1_0.txt or copy at
 // http://www.boost.org/LICENSE_1_0.txt)
 
-// tag::main[]
+#ifndef LIBRARY_NAME
+#ifdef _MSC_VER
+#define LIBRARY_NAME "shared.dll"
+#else
+#define LIBRARY_NAME "libshared.so"
+#endif
+#endif
 
-// dl_main.cpp
+// tag::before[]
+// dynamic_main.cpp
 
 #include "animals.hpp"
 
 #include <boost/openmethod.hpp>
 #include <boost/openmethod/initialize.hpp>
-#include <boost/openmethod/interop/std_unique_ptr.hpp>
-
 #include <boost/dll/shared_library.hpp>
 #include <boost/dll/runtime_symbol_info.hpp>
-
 #include <iostream>
+#include <memory>
 
 using namespace boost::openmethod::aliases;
 
@@ -30,64 +35,68 @@ BOOST_OPENMETHOD_OVERRIDE(
     return "greet";
 }
 
-// end::main[]
-
-// tag::before_dlopen[]
-
-#ifndef LIBRARY_NAME
-#ifdef _MSC_VER
-#define LIBRARY_NAME "shared.dll"
-#else
-#define LIBRARY_NAME "libshared.so"
-#endif
-#endif
-
-auto main() -> int {
-    using namespace boost::openmethod::aliases;
-
+// tag::load[]
+int main() {
+    // end::load[]
+    // end::unload[]
     std::cout << "Before loading the shared library.\n";
+
     initialize();
 
-    {
-        auto gracie = make_unique_virtual<Cow>();
-        auto willy = make_unique_virtual<Wolf>();
+    std::cout << "cow meets wolf -> "
+              << meet(*std::make_unique<Cow>(), *std::make_unique<Wolf>())
+              << "\n"; // greet
+    std::cout << "wolf meets cow -> "
+              << meet(*std::make_unique<Wolf>(), *std::make_unique<Cow>())
+              << "\n"; // greet
+
+    // to be continued...
+    // end::before[]
+    // tag::load[]
+    // ...
 
-        std::cout << "cow meets wolf -> " << meet(*gracie, *willy) << "\n";
-        std::cout << "wolf meets cow -> " << meet(*willy, *gracie) << "\n";
-    }
+    std::cout << "\nAfter loading the shared library.\n";
 
     boost::dll::shared_library lib(
         boost::dll::program_location().parent_path() / LIBRARY_NAME,
         boost::dll::load_mode::rtld_now);
-
-    std::cout << "\nAfter loading the shared library.\n";
-
     initialize();
 
-    {
-        auto gracie = make_unique_virtual<Cow>();
-        auto willy = make_unique_virtual<Wolf>();
+    std::cout << "cow meets wolf -> "
+              << meet(*std::make_unique<Cow>(), *std::make_unique<Wolf>())
+              << "\n"; // run
+    std::cout << "wolf meets cow -> "
+              << meet(*std::make_unique<Wolf>(), *std::make_unique<Cow>())
+              << "\n"; // hunt
 
-        std::cout << "cow meets wolf -> " << meet(*gracie, *willy) << "\n";
-        std::cout << "wolf meets cow -> " << meet(*willy, *gracie) << "\n";
+    auto make_tiger = lib.get<Animal*()>("make_tiger");
+    std::cout << "cow meets tiger -> "
+              << meet(
+                     *std::make_unique<Cow>(),
+                     *std::unique_ptr<Animal>(make_tiger()))
+              << "\n"; // hunt
+                       // end::load[]
 
-        auto make_tiger = lib.get<Animal*()>("make_tiger");
-        std::unique_ptr<Animal> hobbes{make_tiger()};
-        std::cout << "cow meets tiger -> " << meet(*gracie, *hobbes) << "\n";
-    }
+    // tag::unload[]
+    // ...
 
     std::cout << "\nAfter unloading the shared library.\n";
-    lib.unload();
 
+    lib.unload();
     initialize();
 
-    {
-        std::unique_ptr<Animal> gracie(new Cow());
-        std::unique_ptr<Animal> willy(new Wolf());
-
-        std::cout << "cow meets wolf -> " << meet(*gracie, *willy) << "\n";
-        std::cout << "wolf meets cow -> " << meet(*willy, *gracie) << "\n";
-    }
+    std::cout << "cow meets wolf -> "
+              << meet(*std::make_unique<Cow>(), *std::make_unique<Wolf>())
+              << "\n"; // greet
+    std::cout << "wolf meets cow -> "
+              << meet(*std::make_unique<Wolf>(), *std::make_unique<Cow>())
+              << "\n"; // greet
+    // tag::before[]
+    // tag::load[]
+    // tag::unload[]
 
     return 0;
 }
+// end::before[]
+// end::load[]
+// end::unload[]

…ROOT/examples/shared_libs/overriders.cpp …ROOT/examples/shared_libs/extensions.cppdoc/modules/ROOT/examples/shared_libs/overriders.cpp renamed to doc/modules/ROOT/examples/shared_libs/extensions.cpp doc/modules/ROOT/examples/shared_libs/overriders.cpp renamed to doc/modules/ROOT/examples/shared_libs/extensions.cpp

@@ -4,7 +4,7 @@
 // http://www.boost.org/LICENSE_1_0.txt)
 
 // tag::content[]
-// overriders.cpp
+// extensions.cpp
 #include "animals.hpp"
 
 using namespace boost::openmethod::aliases;
@@ -18,4 +18,17 @@ BOOST_OPENMETHOD_OVERRIDE(
     meet, (virtual_ptr<Carnivore>, virtual_ptr<Herbivore>), std::string) {
     return "hunt";
 }
+
+struct Tiger : Carnivore {};
+
+BOOST_OPENMETHOD_CLASSES(Tiger, Carnivore);
+
+extern "C" {
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+auto make_tiger() -> Animal* {
+    return new Tiger;
+}
+}
 // end::content[]

doc/modules/ROOT/examples/shared_libs/indirect_extensions.cpp

@@ -0,0 +1 @@
+#include "extensions.cpp"

doc/modules/ROOT/examples/shared_libs/indirect_main.cpp

@@ -3,29 +3,26 @@
 // accompanying file LICENSE_1_0.txt or copy at
 // http://www.boost.org/LICENSE_1_0.txt)
 
-// tag::main[]
+#ifdef _MSC_VER
+#define LIBRARY_NAME "indirect_shared.dll"
+#else
+#define LIBRARY_NAME "libindirect_shared.so"
+#endif
 
-// dl_main.cpp
+// tag::content[]
+// indirect_main.cpp
 
 #include "animals.hpp"
 
 #include <boost/openmethod.hpp>
 #include <boost/openmethod/initialize.hpp>
 #include <boost/openmethod/interop/std_unique_ptr.hpp>
-
 #include <boost/dll/shared_library.hpp>
 #include <boost/dll/runtime_symbol_info.hpp>
-
 #include <iostream>
 
 using namespace boost::openmethod::aliases;
 
-#ifdef _MSC_VER
-#define LIBRARY_NAME "indirect_shared.dll"
-#else
-#define LIBRARY_NAME "libindirect_shared.so"
-#endif
-
 struct Cow : Herbivore {};
 struct Wolf : Carnivore {};
 
@@ -36,9 +33,6 @@ BOOST_OPENMETHOD_OVERRIDE(
     return "greet";
 }
 
-// end::main[]
-
-// tag::before_dlopen[]
 auto main() -> int {
     using namespace boost::openmethod::aliases;
 
@@ -48,33 +42,23 @@ auto main() -> int {
     auto gracie = make_unique_virtual<Cow>();
     auto willy = make_unique_virtual<Wolf>();
 
-    std::cout << "cow meets wolf -> " << meet(*gracie, *willy) << "\n";
-    std::cout << "wolf meets cow -> " << meet(*willy, *gracie) << "\n";
+    std::cout << "cow meets wolf -> " << meet(*gracie, *willy) << "\n"; // greet
+    std::cout << "wolf meets cow -> " << meet(*willy, *gracie) << "\n"; // greet
+    std::cout << "cow.vptr() = " << gracie.vptr() << "\n"; // 0x5d3121d22be8
+    std::cout << "wolf.vptr() = " << willy.vptr() << "\n"; // 0x5d3121d22bd8
+
+    std::cout << "\nAfter loading the shared library.\n";
 
     boost::dll::shared_library lib(
         boost::dll::program_location().parent_path() / LIBRARY_NAME,
         boost::dll::load_mode::rtld_now);
 
-    std::cout << "\nAfter loading the shared library.\n";
-
-    initialize();
-
-    std::cout << "cow meets wolf -> " << meet(*gracie, *willy) << "\n";
-    std::cout << "wolf meets cow -> " << meet(*willy, *gracie) << "\n";
-
-    {
-        auto make_tiger = lib.get<Animal*()>("make_tiger");
-        std::unique_ptr<Animal> hobbes{make_tiger()};
-        std::cout << "cow meets tiger -> " << meet(*gracie, *hobbes) << "\n";
-    }
-
-    std::cout << "\nAfter unloading the shared library.\n";
-    lib.unload();
-
     initialize();
 
-    std::cout << "cow meets wolf -> " << meet(*gracie, *willy) << "\n";
-    std::cout << "wolf meets cow -> " << meet(*willy, *gracie) << "\n";
+    std::cout << "cow meets wolf -> " << meet(*gracie, *willy) << "\n"; // run
+    std::cout << "wolf meets cow -> " << meet(*willy, *gracie) << "\n"; // hunt
+    std::cout << "cow.vptr() = " << gracie.vptr() << "\n"; // 0x5d3121d21998
+    std::cout << "wolf.vptr() = " << willy.vptr() << "\n"; // 0x5d3121d21988
 
     return 0;
 }

doc/modules/ROOT/examples/shared_libs/indirect_overriders.cpp

@@ -4,8 +4,8 @@
 // http://www.boost.org/LICENSE_1_0.txt)
 
 // tag::content[]
-
 // static_main.cpp
+
 #include "animals.hpp"
 #include <boost/openmethod/initialize.hpp>
 #include <iostream>