C++ Use of wstring_convert on Linux

Question

I would like to be able to convert text read from a file into multibyte characters. I have the following C++ code on Windows that is working for me. When I try to compile the code on Linux though it is failing.

#include <locale>
....
std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>> utfconv;
std::string line;
while (std::getline(infile, line))
{
    std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>> utfconv;
    std::wstring widestr = utfconv.from_bytes(line);

This throws the following errors:

wstring_convert is not a member of std
codecvt_utf8_utf16 is not a member of std
expected primary-expression before wchar_t

I'm using GCC Red Hat 4.4.7-4. Based on what I read, I've imported 'locale', but it still can't find it.

If wstring_convert is not available, is there something equivalent that I can do?

You might want to use `std::u16string` instead of `std::wstring` if your compilers have access to it. I think you can use `std::wstring_convert` with `char16_t` strings. The reason is that `wchar_t` has an implementation-defined size, whereas `char16_t` is specifically for holding UTF-16 characters. — James Picone, Jun 15 '18 at 04:04

score 3 · Accepted Answer · 2018-06-14T23:48:10.790

3

Most likely your standard is not set properly. std::wstring_convert was first introduced in C++11 and deprecated in C++17, so you need to add the compiler flag -std=c++11 or -std=c++14.

EDIT: Just saw the GCC version you're using. It's way out of date. Everything should work fine if you download GCC 4.9.x or above

edited Jun 14 '18 at 23:48

answered Jun 14 '18 at 23:38

Didn't even see that part. :| Editing my answer – Jun 14 '18 at 23:46
@user4581301 I still think 4.8 is too low. It was the first one to even have C++11 support, IIRC – Jun 14 '18 at 23:51
I'm cool with 4.9. There were a few things in the early 4.8s that didn't quite work right. – user4581301 Jun 14 '18 at 23:57
It looks like my version of Linux is very old and I need to upgrade that first. It will be good if that will fix it. – George Hernando Jun 15 '18 at 00:20

score 1 · Answer 2 · answered Jun 15 '18 at 03:58

1

You will have to use a newer GCC version. Precompiled versions are part of Developer Toolset (available as part of most Red Hat Enterprise Linux subscriptions) or as part of Software Collections for CentOS:

devtoolset-7

answered Jun 15 '18 at 03:58

Florian Weimer

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C++ Use of wstring_convert on Linux

2 Answers2