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#pragma once
#include <memory>
#include <fstream>
#include <string>
#include <cassert>
#include "util/Noncopyable.h"
namespace stream
{
/**
* Helper class wrapping around a std::ofstream. The instance can be empty,
* until a filename is been passed to it.
*
* If there is a contained stream, it is ensured that it is
* closed when the instance is destroyed.
*
* The underlying stream can be accessed through the dereference operator*()
*/
class ScopedOutputStream :
public std::ofstream
{
private:
std::unique_ptr<std::ofstream> _stream;
public:
// Constructs an empty stream object, no stream is opened
// until the open() method is invoked
ScopedFileOutputStream()
{}
// Constructs the wrapper and opens the internal stream
// using the given filename
ScopedFileOutputStream(const std::string& filename)
{
open(filename);
}
~ScopedFileOutputStream()
{
if (_stream)
{
_stream->flush();
_stream->close();
_stream.reset();
}
}
// Returns true if there's no underlying stream object instantiated
bool isEmpty() const
{
return static_cast<bool>(_stream);
}
bool isOpen() const
{
return _stream && _stream->is_open();
}
std::ostream& operator*()
{
assert(_stream);
return *_stream;
}
const std::ostream& operator*() const
{
assert(_stream);
return *_stream;
}
// Open the internal stream using the given filename
void open(const std::string& filename)
{
assert(!_stream); // no duplicate open calls
_stream.reset(new std::ofstream(filename));
}
};
}
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