std::wbuffer_convert::wbuffer_convert

C++

Language

Headers

Freestanding and hosted implementations

Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

Localizations library

Locales and facets
locale
use_facet	has_facet
Character classification
isspace isblank (C++11) iscntrl isupper islower isalpha	isdigit ispunct isxdigit isalnum isprint isgraph
Conversions
toupper tolower	wstring_convert (C++11) wbuffer_convert (C++11)
Facet category base classes
ctype_base codecvt_base messages_base	time_base money_base
Facet categories
ctype ctype<char> codecvt collate messages time_get time_put	num_get num_put numpunct money_get money_put moneypunct
Locale-specific facets
ctype_byname codecvt_byname messages_byname collate_byname	time_get_byname time_put_byname numpunct_byname moneypunct_byname
Code conversion facets
codecvt_utf8 (C++11) codecvt_utf16 (C++11)	codecvt_utf8_utf16 (C++11) codecvt_mode (C++11)
C locale
setlocale localeconv lconv	LC_ALLLC_COLLATELC_CTYPELC_MONETARYLC_NUMERICLC_TIME

std::wbuffer_convert

Member functions

wbuffer_convert::wbuffer_convert

wbuffer_convert::~wbuffer_convert

wbuffer_convert::rdbuf

wbuffer_convert::state

wbuffer_convert() : wbuffer_convert(nullptr) { }	(1)
explicit wbuffer_convert( std::streambuf* bytebuf, Codecvt* pcvt = new Codecvt, state_type state = state_type() );	(2)
wbuffer_convert(const std::wbuffer_convert&) = delete;	(3)	(since C++14)

1) Default constructor.

2) Constructs the wbuffer_convert object with the specified underlying byte stream, specified codecvt facet, and specified initial conversion state (all parameters are optional)

3) The copy constructor is deleted, wbuffer_convert is not CopyConstructible

Parameters

bytebuf	-	pointer to std::streambuf to serve as the underlying narrow character stream
pcvt	-	pointer to a standalone (not managed by a locale) std::codecvt facet. The behavior is undefined if this pointer is null.
state	-	the initial value of the character conversion state

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR	Applied to	Behavior as published	Correct behavior
P0935R0	C++11	default constructor was explicit	made implicit

Example

Run this code

#include <iostream>
#include <sstream>
#include <locale>
#include <codecvt>
int main()
{
    // wrap a UTF-8 string stream in a UCS4 wbuffer_convert
    std::stringbuf utf8buf(u8"z\u00df\u6c34\U0001f34c");  // or u8"z"
                       // or "\x7a\xc3\x9f\xe6\xb0\xb4\xf0\x9f\x8d\x8c";
    std::wbuffer_convert<std::codecvt_utf8<wchar_t>> conv_in(&utf8buf);
    std::wistream ucsbuf(&conv_in);
    std::cout << "Reading from a UTF-8 stringbuf via wbuffer_convert:\n";
    for(wchar_t c; ucsbuf.get(c); )
        std::cout << std::hex << std::showbase << c << '\n';

    // wrap a UTF-8 aware std::cout in a UCS4 wbuffer_convert to output UCS4
    std::wbuffer_convert<std::codecvt_utf8<wchar_t>> conv_out(std::cout.rdbuf());
    std::wostream out(&conv_out);
    std::cout << "Sending UCS4 data to std::cout via wbuffer_convert:\n";
    out << L"z\u00df\u6c34\U0001f34c\n";
}

Output:

Reading from a UTF-8 stringbuf via wbuffer_convert produces
0x7a
0xdf
0x6c34
0x1f34c
Sending UCS4 data to std::cout via wbuffer_convert:
z