Fix compilation issues with GCC 4.8

[bryceschober]

Before these changes, building on Ubuntu 14.04 with gcc 4.8 yielded:

$ make all
g++ -c -O3 -Wall -pthread -std=c++11 src/csv_reader.cpp src/csv_stat.cpp src/csv_writer.cpp src/data_type.cpp -Isrc/
src/csv_reader.cpp: In member function ‘void csv::CSVGuesser::second_guess()’:
src/csv_reader.cpp:82:14: warning: variable ‘current_delim’ set but not used [-Wunused-but-set-variable]
         char current_delim;
              ^
src/csv_reader.cpp: In member function ‘bool csv::CSVGuesser::first_guess()’:
src/csv_reader.cpp:68:36: warning: ‘current_delim’ may be used uninitialized in this function [-Wmaybe-uninitialized]
         this->delim = current_delim;
                                    ^
src/csv_writer.cpp: In constructor ‘csv::CSVWriter::CSVWriter(std::string)’:
src/csv_writer.cpp:46:23: error: use of deleted function ‘std::basic_ofstream<char>& std::basic_ofstream<char>::operator=(const std::basic_ofstream<char>&)’
         this->outfile = std::ofstream(outfile, std::ios_base::binary);
                       ^
In file included from src/csv_parser.h:6:0,
                 from src/csv_writer.cpp:1:
/usr/include/c++/4.8/fstream:599:11: note: ‘std::basic_ofstream<char>& std::basic_ofstream<char>::operator=(const std::basic_ofstream<char>&)’ is implicitly deleted because the default definition would be ill-formed:
     class basic_ofstream : public basic_ostream<_CharT,_Traits>
           ^
/usr/include/c++/4.8/fstream:599:11: error: use of deleted function ‘std::basic_ostream<char>& std::basic_ostream<char>::operator=(const std::basic_ostream<char>&)’
In file included from /usr/include/c++/4.8/iostream:39:0,
                 from src/csv_parser.h:5,
                 from src/csv_writer.cpp:1:
/usr/include/c++/4.8/ostream:58:11: note: ‘std::basic_ostream<char>& std::basic_ostream<char>::operator=(const std::basic_ostream<char>&)’ is implicitly deleted because the default definition would be ill-formed:
     class basic_ostream : virtual public basic_ios<_CharT, _Traits>
           ^
/usr/include/c++/4.8/ostream:58:11: error: use of deleted function ‘std::basic_ios<char>& std::basic_ios<char>::operator=(const std::basic_ios<char>&)’
In file included from /usr/include/c++/4.8/ios:44:0,
                 from /usr/include/c++/4.8/ostream:38,
                 from /usr/include/c++/4.8/iostream:39,
                 from src/csv_parser.h:5,
                 from src/csv_writer.cpp:1:
/usr/include/c++/4.8/bits/basic_ios.h:66:11: note: ‘std::basic_ios<char>& std::basic_ios<char>::operator=(const std::basic_ios<char>&)’ is implicitly deleted because the default definition would be ill-formed:
     class basic_ios : public ios_base
           ^
In file included from /usr/include/c++/4.8/ios:42:0,
                 from /usr/include/c++/4.8/ostream:38,
                 from /usr/include/c++/4.8/iostream:39,
                 from src/csv_parser.h:5,
                 from src/csv_writer.cpp:1:
/usr/include/c++/4.8/bits/ios_base.h:795:5: error: ‘std::ios_base& std::ios_base::operator=(const std::ios_base&)’ is private
     operator=(const ios_base&);
     ^
In file included from /usr/include/c++/4.8/ios:44:0,
                 from /usr/include/c++/4.8/ostream:38,
                 from /usr/include/c++/4.8/iostream:39,
                 from src/csv_parser.h:5,
                 from src/csv_writer.cpp:1:
/usr/include/c++/4.8/bits/basic_ios.h:66:11: error: within this context
     class basic_ios : public ios_base
           ^
In file included from src/csv_parser.h:6:0,
                 from src/csv_writer.cpp:1:
/usr/include/c++/4.8/fstream:599:11: error: use of deleted function ‘std::basic_filebuf<char>& std::basic_filebuf<char>::operator=(const std::basic_filebuf<char>&)’
     class basic_ofstream : public basic_ostream<_CharT,_Traits>
           ^
/usr/include/c++/4.8/fstream:72:11: note: ‘std::basic_filebuf<char>& std::basic_filebuf<char>::operator=(const std::basic_filebuf<char>&)’ is implicitly deleted because the default definition would be ill-formed:
     class basic_filebuf : public basic_streambuf<_CharT, _Traits>
           ^
In file included from /usr/include/c++/4.8/ios:43:0,
                 from /usr/include/c++/4.8/ostream:38,
                 from /usr/include/c++/4.8/iostream:39,
                 from src/csv_parser.h:5,
                 from src/csv_writer.cpp:1:
/usr/include/c++/4.8/streambuf:810:7: error: ‘std::basic_streambuf<_CharT, _Traits>& std::basic_streambuf<_CharT, _Traits>::operator=(const std::basic_streambuf<_CharT, _Traits>&) [with _CharT = char; _Traits = std::char_traits<char>]’ is private
       operator=(const basic_streambuf&) { return *this; };
       ^
In file included from src/csv_parser.h:6:0,
                 from src/csv_writer.cpp:1:
/usr/include/c++/4.8/fstream:72:11: error: within this context
     class basic_filebuf : public basic_streambuf<_CharT, _Traits>
           ^
make: *** [csv_parser] Error 1

After these changes, I have no warnings or errors, and all tests passed:

$ make all
g++ -c -O3 -Wall -pthread -std=c++11 src/csv_reader.cpp src/csv_stat.cpp src/csv_writer.cpp src/data_type.cpp -Isrc/
mkdir -p build
mv *.o build
make run_test_csv_parser
make[1]: Entering directory `/home/bschober/git/dynon-csv-parser'
g++ -o test_csv_parser src/csv_reader.cpp src/csv_stat.cpp src/csv_writer.cpp src/data_type.cpp tests/main.cpp tests/test_csv_stat.cpp tests/test_data_type.cpp tests/test_read_csv.cpp tests/test_write_csv.cpp -Isrc/ -Itests/ -pthread -std=c++11 -Og -g --coverage
mkdir -p tests/temp
./test_csv_parser
===============================================================================
All tests passed (116078 assertions in 34 test cases)

# Test Clean-Up
rm -rf tests/temp
make[1]: Leaving directory `/home/bschober/git/dynon-csv-parser'
make code_cov
make[1]: Entering directory `/home/bschober/git/dynon-csv-parser'
mkdir -p test_results
mv *.gcno *.gcda /home/bschober/git/dynon-csv-parser/test_results
gcov src/csv_reader.cpp src/csv_stat.cpp src/csv_writer.cpp src/data_type.cpp -o test_results --relative-only
File 'src/csv_reader.cpp'
Lines executed:95.61% of 296
Creating 'csv_reader.cpp.gcov'

File 'src/csv_parser.h'
Lines executed:95.24% of 21
Creating 'csv_parser.h.gcov'

File 'src/csv_stat.cpp'
Lines executed:97.96% of 98
Creating 'csv_stat.cpp.gcov'

File 'src/csv_writer.cpp'
Lines executed:98.15% of 54
Creating 'csv_writer.cpp.gcov'

File 'src/data_type.cpp'
Lines executed:100.00% of 16
Creating 'data_type.cpp.gcov'

Lines executed:96.49% of 485
mv *.gcov test_results
make[1]: Leaving directory `/home/bschober/git/dynon-csv-parser'
rm -rf test_csv_parser

[bryceschober]

Fixes possible use without initialization.

[bryceschober]

Was unused in this context, so I deleted it.

[bryceschober]

GCC 4.8's libstdc++'s ofstream doesn't support copy or move, so just use open().

[codecov]

Codecov Report

Merging #4 into master will decrease coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff            @@
##           master      #4      +/-   ##
=========================================
- Coverage    96.7%   96.7%   -0.01%     
=========================================
  Files           5       5              
  Lines         486     485       -1     
=========================================
- Hits          470     469       -1     
  Misses         16      16

Impacted Files	Coverage Δ
src/csv_reader.cpp	95.93% <ø> (-0.02%)	⬇️
src/csv_writer.cpp	98.03% <100%> (ø)	⬆️

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[vincentlaucsb]

Hi there! Thanks for fixing some issues I've been meaning to get to for a while. -Vince