template <typename TValue>

bool operator()(TFile& _file, TValue& value,

typename std::enable_if< std::is_same<TValue,TFileValue>::value>::type* dummy=0) const {

return _file.read(value);

}

template <typename TValue>

bool operator()(TFile& _file, TValue& value,

typename std::enable_if< !std::is_same<TValue,TFileValue>::value>::type* dummy=0) const {

TFileValue val;

const bool result= _file.read(val);

if (result) {

value= val;

return true;

}

return false;

}

{

typedef TFileValue filevalue_t;

typedef TFile file_t;

typedef TValue value_t;

typedef TReader reader_t;

const reader_t _reader;

const std::string _filename;

file_t _file;

value_t _current_value;

BWTPosition _current_position;

bool _terminated;

// Constructors

SingleFileIterator(const std::string& filename)

:_reader(), _filename(filename)

{

open();

}

// Destructor

~SingleFileIterator() {

close();

}

SingleFileIterator& operator++() {

_FAIL_IF_DBG(_terminated);

++_current_position;

const bool valid = _reader(_file, _current_value);

_terminated = !valid;

return *this;

}

TValue operator*() const {

_FAIL_IF_DBG(_terminated);

return _current_value;

}

BWTPosition get_position() const {

return _current_position;

}

void reset() {

close();

open();

}

bool terminated() const {

return _terminated;

}

// no need of copy ctor nor assignment operator

SingleFileIterator();

SingleFileIterator(const SingleFileIterator<TFileValue,TFile,TValue,TReader>&);

SingleFileIterator<TFileValue,TValue>&

operator=(const SingleFileIterator<TFileValue,TFile,TValue,TReader>&);

void open() {

DEBUG_LOG_VERBOSE("Initializing SingleFileIterator on file: " << _filename);

const bool result= _file.open(_filename);

if (!result) {

DEBUG_LOG("Impossible to open file '" << _filename << "' for reading.");

throw std::logic_error(std::string("Impossible to open file '")

+ _filename + "' for reading.");

}

DEBUG_LOG_VERBOSE("File '" << _filename << "' successfully opened.");

const bool valid = _reader(_file, _current_value);

_current_position= 0;

_terminated = !valid;

}

void close() {

DEBUG_LOG_VERBOSE("Closing SingleFileIterator on file: " << _filename);

_file.close();

_current_position= 0;

_terminated= true;

}