basic_ofstream(const basic_ofstream&) = delete

RM

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Oct 6, 2020, 6:11:25 AM10/6/20

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When trying to output xml_document of rapidxml library:

ofstream xml_file(xml_filepath.c_str());
print(xml_file, doc, 0);

I recive error:

src/cache.cpp: In function ‘void save_cache(std::__cxx11::string, const
char*, const char*, std::__cxx11::string, std::__cxx11::string,
std::__cxx11::string, bool&, const identifiers_vector (&)[5], const
std::unordered_map<std::__cxx11::basic_string<char>,
apostrophed_strings_map>*)’:
src/cache.cpp:204:27: error: use of deleted function
‘std::basic_ofstream<_CharT, _Traits>::basic_ofstream(const
std::basic_ofstream<_CharT, _Traits>&) [with _CharT = char; _Traits =
std::char_traits<char>]’
print(xml_file, doc, 0);
^
In file included from src/cache.cpp:14:0:
/usr/include/c++/7/fstream:723:7: note: declared here
basic_ofstream(const basic_ofstream&) = delete;
^~~~~~~~~~~~~~

How can I solve the problem of deleted function?

Bonita Montero

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Oct 6, 2020, 6:59:21 AM10/6/20

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Define a proper print-function that takes a _reference_ to the stream.

Öö Tiib

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Oct 6, 2020, 7:04:22 AM10/6/20

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On Tuesday, 6 October 2020 13:11:25 UTC+3, RM wrote:
> When trying to output xml_document of rapidxml library:
>
> ofstream xml_file(xml_filepath.c_str());
> print(xml_file, doc, 0);

You post again what does not even compile? Your print function
is bad. This time about
some kind of library that probably hasn't been maintained for more
than 10 years?

> How can I solve the problem of deleted function?

Streams are not copyable so copy constructor is deleted. You solve
your problem with it by not attempting to copy streams.

Bonita Montero

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Oct 6, 2020, 7:07:10 AM10/6/20

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I'm wondering why he is dealing with such beyond-n00b-topics like
doing xml-processing and not even knowing how to define the print
function properly.

Öö Tiib

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Oct 6, 2020, 7:51:01 AM10/6/20

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I suspect that the reason is that there are not enough stand-alone
interesting novice programming missions but to do something actually
useful isn't easy.

For example try to communicate with some useful online service.
Those often reply to requests with xml, csv, yaml or json. Same
is with data or config files of some on-premise program. Such
are often whole compressed directories of huge structured text
files. For me it is piece of cake ... but for novice in world
full of various garbage libraries it is hilly territory.

James Kuyper

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Oct 6, 2020, 12:10:50 PM10/6/20

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From what you've told us so far, the only thing we can say is "don't do
that". It would be easier to provide a useful answer to that question if
you would provide the source code for save_cache() from src/cache.cpp.

Bonita Montero

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Oct 6, 2020, 1:03:06 PM10/6/20

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> From what you've told us so far, the only thing we can say is "don't do
> that". It would be easier to provide a useful answer to that question if
> you would provide the source code for save_cache() from src/cache.cpp.

Not necessary.
He is obviously passing an ofstream by value and not by referrence.

Juha Nieminen

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Oct 7, 2020, 2:25:53 AM10/7/20

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RM <robert_m...@wp.pl> wrote:
> When trying to output xml_document of rapidxml library:
>
> ofstream xml_file(xml_filepath.c_str());
> print(xml_file, doc, 0);
>
> I recive error:

We are supposed to guess how that print() function is declared?

Bonita Montero

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Oct 7, 2020, 3:10:26 AM10/7/20

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>> When trying to output xml_document of rapidxml library:
>>
>> ofstream xml_file(xml_filepath.c_str());
>> print(xml_file, doc, 0);
>>
>> I recive error:

> We are supposed to guess how that print() function is declared?

You don't have to know it exactly, but it takes a ofstream
-object without a reference for sure.