std::wstring_convert<Codecvt,Elem,Wide_alloc,Byte_alloc>::to_bytes
From cppreference.com
< cpp | locale | wstring convert
Defined in header <locale>
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byte_string to_bytes( Elem wchar ); |
(1) | |
byte_string to_bytes( const Elem* wptr ); |
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byte_string to_bytes( const wide_string& wstr ); |
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byte_string to_bytes(
const Elem* first, const Elem* last )
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Converts a wide sequence to a byte string using the facet pointed to by cvtptr .
1) The wide sequence only consists of one element byte.
2) The wide sequence is the null-terminated sequence beginning at ptr.
3) The wide sequence is the sequence contained in str.
4) The wide sequence is the range
[first, last)
Before the conversion begins, if *this was not constructed with constructor overload (3), cvtstate
The number of input elements successfully converted will be stored in cvtcount .
Return value
If the conversion succeeds, returns the conversion result. Otherwise, if *this is constructed with constructor overload (4), returns byte_err_string
Exceptions
If the conversion fails and *this was not constructed with constructor overload (4), throws std::range_error
Example
Run this code
#include <codecvt> #include <iomanip> #include <iostream> #include <locale> #include <string> // 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) |
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| converts a wide string to narrow multibyte character string, given state (function) |
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[virtual]
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converts a string from InternT to ExternT, such as when writing to file (virtual protected member function of std::codecvt<InternT,ExternT,StateT>) |