60 lines
1.6 KiB
C++
60 lines
1.6 KiB
C++
/*
|
|
Copyright (c) 2013 Microsoft Corporation. All rights reserved.
|
|
Released under Apache 2.0 license as described in the file LICENSE.
|
|
|
|
Author: Leonardo de Moura
|
|
*/
|
|
#pragma once
|
|
#include <iostream>
|
|
#include <fstream>
|
|
#include <sstream>
|
|
#include <string>
|
|
|
|
namespace lean {
|
|
/**
|
|
\brief Wrapper for std::ostream.
|
|
The idea is to be able to have an output stream that can be
|
|
"reassigned".
|
|
|
|
std::unique_ptr<output_channel> out;
|
|
out = new stdout_channel();
|
|
(*out) << "writting to standard output";
|
|
out = new stderr_channel();
|
|
(*out) << "writting to standard input";
|
|
out = new file_output_channel("file.txt");
|
|
(*out) << "writting to file";
|
|
*/
|
|
class output_channel {
|
|
public:
|
|
virtual ~output_channel() {}
|
|
virtual std::ostream & get_stream() = 0;
|
|
};
|
|
class stdout_channel : public output_channel {
|
|
public:
|
|
virtual std::ostream & get_stream() { return std::cout; }
|
|
};
|
|
class stderr_channel : public output_channel {
|
|
public:
|
|
virtual std::ostream & get_stream() { return std::cerr; }
|
|
};
|
|
class file_output_channel : public output_channel {
|
|
std::ofstream m_out;
|
|
public:
|
|
file_output_channel(char const * fname):m_out(fname) {}
|
|
virtual ~file_output_channel() {}
|
|
virtual std::ostream & get_stream() { return m_out; }
|
|
};
|
|
class string_output_channel : public output_channel {
|
|
std::ostringstream m_out;
|
|
public:
|
|
string_output_channel() {}
|
|
virtual ~string_output_channel() {}
|
|
virtual std::ostream & get_stream() { return m_out; }
|
|
std::string str() const { return m_out.str(); }
|
|
};
|
|
template<typename T>
|
|
output_channel & operator<<(output_channel & out, T const & v) {
|
|
out.get_stream() << v;
|
|
return out;
|
|
}
|
|
}
|