modernize use nullptr (python binding) (#896)

bindings/python/src/alert.cpp

@@ -346,7 +346,7 @@ void bind_alert()
         ;
 
     class_<read_piece_alert, bases<torrent_alert>, noncopyable>(
-        "read_piece_alert", 0, no_init)
+        "read_piece_alert", nullptr, no_init)
         .add_property("buffer", get_buffer)
         .def_readonly("piece", &read_piece_alert::piece)
         .def_readonly("size", &read_piece_alert::size)

bindings/python/src/converters.cpp

@@ -33,15 +33,15 @@ struct tuple_to_endpoint
 
     static void* convertible(PyObject* x)
     {
-        if (!PyTuple_Check(x)) return NULL;
+        if (!PyTuple_Check(x)) return nullptr;
-        if (PyTuple_Size(x) != 2) return NULL;
+        if (PyTuple_Size(x) != 2) return nullptr;
         extract<std::string> ip(object(borrowed(PyTuple_GetItem(x, 0))));
-        if (!ip.check()) return NULL;
+        if (!ip.check()) return nullptr;
         extract<int> port(object(borrowed(PyTuple_GetItem(x, 1))));
-        if (!port.check()) return NULL;
+        if (!port.check()) return nullptr;
         lt::error_code ec;
         lt::address::from_string(ip, ec);
-        if (ec) return NULL;
+        if (ec) return nullptr;
         return x;
     }
 
@@ -78,7 +78,7 @@ struct tuple_to_pair
 
     static void* convertible(PyObject* x)
     {
-        return (PyTuple_Check(x) && PyTuple_Size(x) == 2) ? x: NULL;
+        return (PyTuple_Check(x) && PyTuple_Size(x) == 2) ? x: nullptr;
     }
 
     static void construct(PyObject* x, converter::rvalue_from_python_stage1_data* data)
@@ -121,7 +121,7 @@ struct list_to_vector
 
     static void* convertible(PyObject* x)
     {
-        return PyList_Check(x) ? x: 0;
+        return PyList_Check(x) ? x: nullptr;
     }
 
     static void construct(PyObject* x, converter::rvalue_from_python_stage1_data* data)

bindings/python/src/create_torrent.cpp

@@ -76,7 +76,7 @@ namespace
 
         FileIter(file_storage const& fs, int i) : m_fs(&fs), m_i(i) {}
         FileIter(FileIter const& fi) : m_fs(fi.m_fs), m_i(fi.m_i) {}
-        FileIter() : m_fs(NULL), m_i(0) {}
+        FileIter() : m_fs(nullptr), m_i(0) {}
         libtorrent::file_entry operator*() const
         { return m_fs->at(m_i); }
 

bindings/python/src/session.cpp

@@ -794,7 +794,7 @@ void bind_session()
 #ifndef TORRENT_NO_DEPRECATE
         .def(
             "listen_on", &listen_on
-          , (arg("min"), "max", arg("interface") = (char const*)0, arg("flags") = 0)
+          , (arg("min"), "max", arg("interface") = (char const*)nullptr, arg("flags") = 0)
         )
 #ifndef TORRENT_DISABLE_DHT
         .def("start_dht", allow_threads(start_dht0))

bindings/python/src/string.cpp

@@ -21,7 +21,7 @@ struct unicode_from_python
 #if PY_VERSION_HEX >= 0x03020000
         return PyBytes_Check(x) ? x : PyUnicode_Check(x) ? x : 0;
 #else
-        return PyString_Check(x) ? x : PyUnicode_Check(x) ? x : 0;
+        return PyString_Check(x) ? x : PyUnicode_Check(x) ? x : nullptr;
 #endif
     }
 
@@ -33,7 +33,7 @@ struct unicode_from_python
         if (PyUnicode_Check(x))
         {
             PyObject* utf8 = PyUnicode_AsUTF8String(x);
-            if (utf8 == NULL)
+            if (utf8 == nullptr)
             {
                new (storage) std::string();
             }

bindings/python/src/utility.cpp

@@ -42,7 +42,7 @@ struct bytes_from_python
 #if PY_MAJOR_VERSION >= 3
         return PyBytes_Check(x) ? x : NULL;
 #else
-        return PyString_Check(x) ? x : NULL;
+        return PyString_Check(x) ? x : nullptr;
 #endif
     }