Add a sample which shows how to deal with C++ libraries.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@2394 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ext/dl/MANIFEST

@@ -17,6 +17,8 @@ mkcall.rb
 mkcallback.rb
 mkcbtable.rb
 ptr.c
+sample/c++sample.C
+sample/c++sample.rb
 sample/drives.rb
 sample/getch.rb
 sample/libc.rb

ext/dl/sample/c++sample.C

@@ -0,0 +1,35 @@
+#include <stdio.h>
+
+class Person {
+private:
+  const char *name;
+  int age;
+
+public:
+  Person(const char *name, int age);
+  const char * get_name();
+  int get_age();
+  void set_age(int i);
+};
+
+Person::Person(const char *name, int age)
+  : name(name), age(age)
+{
+  /* empty */
+}
+
+const char *
+Person::get_name()
+{
+  return name;
+}
+
+int
+Person::get_age(){
+  return age;
+}
+
+void
+Person::set_age(int i){
+  age = i;
+}

ext/dl/sample/c++sample.rb

@@ -0,0 +1,60 @@
+=begin
+ This script shows how to deal with C++ classes using Ruby/DL.
+ You must build a dynamic loadable library using "c++sample.C"
+ to run this script as follows:
+   $ g++ -o libsample.so -shared c++sample.C
+=end
+
+require 'dl'
+require 'dl/import'
+require 'dl/struct'
+
+# Give a name of dynamic loadable library
+LIBNAME = ARGV[0] || "libsample.so"
+
+class Person
+  module Core
+    extend DL::Importable
+    
+    dlload LIBNAME
+
+    # mangled symbol names
+    extern "void __6PersonPCci(void *, const char *, int)"
+    extern "const char *get_name__6Person(void *)"
+    extern "int get_age__6Person(void *)"
+    extern "void set_age__6Personi(void *, int)"
+
+    Data = struct [
+      "char *name",
+      "int age",
+    ]
+  end
+
+  def initialize(name, age)
+    @ptr = Core::Data.alloc
+    Core::__6PersonPCci(@ptr, name, age)
+  end
+
+  def get_name()
+    str = Core::get_name__6Person(@ptr)
+    if( str )
+      str.to_s
+    else
+      nil
+    end
+  end
+
+  def get_age()
+    Core::get_age__6Person(@ptr)
+  end
+
+  def set_age(age)
+    Core::set_age__6Personi(@ptr, age)
+  end
+end
+
+obj = Person.new("ttate", 1)
+p obj.get_name()
+p obj.get_age()
+obj.set_age(10)
+p obj.get_age()