public member function
<locale>
wbuffer_convert (streambuf* bytebuf = nullptr, Codecvt* pcvt = new Codecvt, state_type state = state_type());
explicit wbuffer_convert (streambuf* bytebuf = nullptr, Codecvt* pcvt = new Codecvt, state_type state = state_type()); wbuffer_convert (const wbuffer_convert&) = delete;
Construct wbuffer_convert
Constructs a wbuffer_convert object with its internal state initialized to the arguments passed.
The object wraps a bytebuf object, which becomes its underlying byte stream buffer.
wbuffer_convert objects cannot be copied (both the copy-constructor and copy-assignment are deleted). [C++14]
Parameters
- bytebuf
- Pointer to the underlying byte stream buffer.
streambuf is a standard instantiation of template basic_streambuf for elements of type char (defined in header <streambuf>).
- pcvt
- Pointer to a conversion object (such as those of the types declared in <codecvt>) whose storage has already been allocated with
new.
The constructed object acquires ownership of this conversion object, which is automatically destroyed (with operator delete) when this object is destroyed. Note that this makes facets managed by locale objects not suitable to be used by wbuffer_convert.
If a null pointer is passed, it causes undefined behavior.
Codecvt is the first template parameter of wbuffer_convert (its conversion object's type).
- state
- Initial conversion shift state. The state is carried onto the next conversion operation.
state_type is a member type, defined as an alias of Codecvt::state_type (where Codecvt is the first template parameter of wbuffer_convert).
Example
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// wbuffer_convert example
#include <iostream> // std::cout, std::ios, std::wostream
#include <locale> // std::wbuffer_convert
#include <codecvt> // std::codecvt_utf8
#include <fstream> // std::filebuf
int main ()
{
// file buffer (narrow buffer):
std::filebuf myfile;
myfile.open("test.txt",std::ios::out|std::ios::binary);
// conversor (wide buffer -> narrow buffer, using UTF-8):
std::wbuffer_convert<std::codecvt_utf8<wchar_t>> bufconv (&myfile);
// stream (wide buffer):
std::wostream mystream (&bufconv);
mystream << L"Test"; // writes wide string to file (UTF-8)
return 0;
}
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Data races
bytebuf and pcvt may be accessed/modified by future operations on the object.
Management of the storage for the element pointed by pcvt (if any) is acquired by the constructed object.
Exception safety
Strong guarantee: no effects in case an exception is thrown.