136 lines
4.3 KiB
C++
136 lines
4.3 KiB
C++
/////////////////////////////////////////////////////////////////////////////
|
|
// apps/examples/elf/tests/helloxx/hello++4.cxx
|
|
//
|
|
// Licensed to the Apache Software Foundation (ASF) under one or more
|
|
// contributor license agreements. See the NOTICE file distributed with
|
|
// this work for additional information regarding copyright ownership. The
|
|
// ASF licenses this file to you under the Apache License, Version 2.0 (the
|
|
// "License"); you may not use this file except in compliance with the
|
|
// License. You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
// License for the specific language governing permissions and limitations
|
|
// under the License.
|
|
//
|
|
/////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// This is an excessively complex version of "Hello, World" design to
|
|
// illustrate some basic properties of C++:
|
|
//
|
|
// - Building a C++ program
|
|
// - Streams / statically linked libstdc++
|
|
// - Static constructor and destructors (in main program only)
|
|
//
|
|
/////////////////////////////////////////////////////////////////////////////
|
|
|
|
/////////////////////////////////////////////////////////////////////////////
|
|
// Included Files
|
|
/////////////////////////////////////////////////////////////////////////////
|
|
|
|
#include <cstdio>
|
|
#include <iostream>
|
|
|
|
#ifndef NULL
|
|
# define NULL ((void*)0L)
|
|
#endif
|
|
|
|
/////////////////////////////////////////////////////////////////////////////
|
|
// Classes
|
|
/////////////////////////////////////////////////////////////////////////////
|
|
|
|
using namespace std;
|
|
|
|
// A hello world sayer class
|
|
|
|
class CThingSayer
|
|
{
|
|
const char *szWhatToSay;
|
|
public:
|
|
CThingSayer(void);
|
|
virtual ~CThingSayer(void);
|
|
virtual void Initialize(const char *czSayThis);
|
|
virtual void SayThing(void);
|
|
};
|
|
|
|
/////////////////////////////////////////////////////////////////////////////
|
|
// Private Data
|
|
/////////////////////////////////////////////////////////////////////////////
|
|
|
|
// A static instance of the CThingSayer class. This instance MUST
|
|
// be constructed by the system BEFORE the program is started at
|
|
// main() and must be destructed by the system AFTER the main()
|
|
// returns to the system
|
|
|
|
static CThingSayer MyThingSayer;
|
|
|
|
/////////////////////////////////////////////////////////////////////////////
|
|
// Method Implementations
|
|
/////////////////////////////////////////////////////////////////////////////
|
|
|
|
// These are implementations of the methods of the CThingSayer class
|
|
|
|
CThingSayer::CThingSayer(void)
|
|
{
|
|
cout << "CThingSayer::CThingSayer: I am!" << endl;
|
|
szWhatToSay = NULL;
|
|
}
|
|
|
|
CThingSayer::~CThingSayer(void)
|
|
{
|
|
cout << "CThingSayer::~CThingSayer: I cease to be" << endl;
|
|
if (szWhatToSay)
|
|
{
|
|
cout << "CThingSayer::~CThingSayer: I will never say '"
|
|
<< szWhatToSay << "' again" << endl;
|
|
}
|
|
szWhatToSay = NULL;
|
|
}
|
|
|
|
void CThingSayer::Initialize(const char *czSayThis)
|
|
{
|
|
cout << "CThingSayer::Initialize: When told, I will say '"
|
|
<< czSayThis << "'" << endl;
|
|
szWhatToSay = czSayThis;
|
|
}
|
|
|
|
void CThingSayer::SayThing(void)
|
|
{
|
|
cout << "CThingSayer::SayThing: I am now saying '"
|
|
<< szWhatToSay << "'" << endl;
|
|
}
|
|
|
|
/////////////////////////////////////////////////////////////////////////////
|
|
// Public Functions
|
|
/////////////////////////////////////////////////////////////////////////////
|
|
|
|
int main(int argc, char **argv)
|
|
{
|
|
// We should see the message from constructor, CThingSayer::CThingSayer(),
|
|
// BEFORE we see the following messages. That is proof that the
|
|
// C++ static initializer is working
|
|
|
|
cout << "main: Started" << endl;
|
|
|
|
// Tell MyThingSayer that "Hello, World!" is the string to be said
|
|
|
|
cout << "main: Calling MyThingSayer.Initialize" << endl;
|
|
MyThingSayer.Initialize("Hello, World!");
|
|
|
|
// Tell MyThingSayer to say the thing we told it to say
|
|
|
|
cout << "main: Calling MyThingSayer.SayThing" << endl;
|
|
MyThingSayer.SayThing();
|
|
|
|
// We are finished, return. We should see the message from the
|
|
// destructor, CThingSayer::~CThingSayer(), AFTER we see the following
|
|
// message. That is proof that the C++ static destructor logic
|
|
// is working
|
|
|
|
cout << "main: Returning" << endl;
|
|
return 0;
|
|
}
|