std::wstring_convert<Codecvt,Elem,Wide_alloc,Byte_alloc>::to_bytes
Defined in header <locale> |
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|---|---|---|
byte_string to_bytes( Elem wchar ); |
(1) | |
byte_string to_bytes( const Elem* wptr ); |
(2) | |
byte_string to_bytes( const wide_string& wstr ); |
(3) | |
byte_string to_bytes( const Elem* first, const Elem* last); |
(4) |
Performs wide to multibyte conversion, using the codecvt facet supplied at construction.
wchar as if it was a string of length
1, to
byte_string.
wptr, to
byte_string.
str to
byte_string.
[first, last) to
byte_string.
In all cases, the conversion begins in initial shift state, unless non-initial starting state was provided to this wstring_convert constructor. The number of characters converted and the final value of the conversion state are remembered and can be accessed with state() and converted().
Return value
A byte_string object containing the results of the wide to multibyte conversion. If the conversion failed and there was a user-supplied byte-error string provided to the constructor of this wstring_convert, returns that byte-error string.
Exceptions
If this wstring_convert object was constructed without a user-supplied byte-error string, throws std::range_error on conversion failure.
Example
#include <iostream>
#include <string>
#include <locale>
#include <codecvt>
#include <iomanip>
// utility function for output
void hex_print(const std::string& s)
{
std::cout << std::hex << std::setfill('0');
for(unsigned char c : s)
std::cout << std::setw(2) << static_cast<int>(c) << ' ';
std::cout << std::dec << '\n';
}
int main()
{
// wide character data
std::wstring wstr = L"z\u00df\u6c34\U0001f34c"; // or L"zß水🍌"
// wide to UTF-8
std::wstring_convert<std::codecvt_utf8<wchar_t>> conv1;
std::string u8str = conv1.to_bytes(wstr);
std::cout << "UTF-8 conversion produced " << u8str.size() << " bytes:\n";
hex_print(u8str);
// wide to UTF-16le
std::wstring_convert<std::codecvt_utf16<wchar_t, 0x10ffff, std::little_endian>> conv2;
std::string u16str = conv2.to_bytes(wstr);
std::cout << "UTF-16le conversion produced " << u16str.size() << " bytes:\n";
hex_print(u16str);
}
Output:
UTF-8 conversion produced 10 bytes: 7a c3 9f e6 b0 b4 f0 9f 8d 8c UTF-16le conversion produced 10 bytes: 7a 00 df 00 34 6c 3c d8 4c df
See also
| converts a byte string into a wide string (public member function) |
|
| converts a wide string to narrow multibyte character string, given state (function) |
|
|
[virtual]
|
converts a string from internT to externT, such as when writing to file (virtual protected member function of std::codecvt<InternT,ExternT,State>) |
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