cpp-scoped-buffer-capture/include/scoped_buffer_capture.h

//
//  scoped_buffer_capture.h
//  scoped_buffer_capture
//
//  Created by Sam Jaffe on 6/2/18.
//

#pragma once

class scoped_buffer_capture_t {
public:
  scoped_buffer_capture_t(std::ostream & stream)
  : buffer()
  , sbuf(stream.rdbuf())
  , out(&stream) {
    out->rdbuf(buffer.rdbuf());
  }
  
  ~scoped_buffer_capture_t() {
    out->rdbuf(sbuf);
  }
  
  scoped_buffer_capture_t(scoped_buffer_capture_t const &) = delete;
  scoped_buffer_capture_t & operator=(scoped_buffer_capture_t const &) = delete;
  scoped_buffer_capture_t(scoped_buffer_capture_t &&) = delete;
  scoped_buffer_capture_t & operator=(scoped_buffer_capture_t &&) = delete;

  std::string str() const { return buffer.str(); }
private:
  std::stringstream buffer;
  std::streambuf * sbuf;
  std::ostream * out;
};

#define capture_stdout() scoped_buffer_capture_t cap_cout(std::cout)
#define capture_stderr() scoped_buffer_capture_t cap_cerr(std::cerr)