Adding upstream version 1.44.3.upstream/1.44.3

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 78 insertions, 0 deletions

diff --git a/ml/dlib/examples/member_function_pointer_ex.cpp b/ml/dlib/examples/member_function_pointer_ex.cpp
new file mode 100644
index 000000000..26724d3a3
--- /dev/null
+++ b/ml/dlib/examples/member_function_pointer_ex.cpp
@@ -0,0 +1,78 @@
+// The contents of this file are in the public domain. See LICENSE_FOR_EXAMPLE_PROGRAMS.txt
+
+/*
+    This is an example illustrating the use of the member_function_pointer object 
+    from the dlib C++ Library.
+
+*/
+
+
+#include <iostream>
+#include <dlib/member_function_pointer.h>
+
+using namespace dlib;
+using namespace std;
+
+// ----------------------------------------------------------------------------------------
+
+class example_object 
+{
+public:
+
+    void do_something (
+    )
+    {
+        cout << "hello world" << endl;
+    }
+
+    void print_this_number (
+        int num
+    )
+    {
+        cout << "number you gave me = " << num << endl;
+    }
+
+};
+
+// ----------------------------------------------------------------------------------------
+
+int main()
+{
+    // create a pointer that can point to member functions that take no arguments
+    member_function_pointer<> mfp1;
+
+    // create a pointer that can point to member functions that take a single int argument
+    member_function_pointer<int> mfp2;
+
+    example_object obj;
+
+    // now we set the mfp1 pointer to point to the member function do_something() 
+    // on the obj object.
+    mfp1.set(obj, &example_object::do_something);
+
+
+    // now we set the mfp1 pointer to point to the member function print_this_number() 
+    // on the obj object.
+    mfp2.set(obj, &example_object::print_this_number);
+
+
+    // Now we can call the function this pointer points to.  This calls the function
+    // obj.do_something() via our member function pointer.
+    mfp1();
+
+    // Now we can call the function this pointer points to.  This calls the function
+    // obj.print_this_number(5) via our member function pointer.
+    mfp2(5);
+
+
+    // The above example shows a very simple use of the member_function_pointer. 
+    // A more interesting use of the member_function_pointer is in the implementation
+    // of callbacks or event handlers.  For example, when you register an event
+    // handler for a dlib::button click it uses a member_function_pointer 
+    // internally to save and later call your event handler.  
+}
+
+// ----------------------------------------------------------------------------------------
+
+
+